Jaguar XJC V12 update. Engine issues mean it's back in the workshop for a new fuel injection system

[@johna1160]

Rarely am I interested in Harry's reviews of pricey new automobiles. But when he takes one of his classics to an expert, and takes us along, I absolutely love it! Throwing your son under the bus like that, honestly Harry...

[@ChifundoBanda]

Poor Charlie didn't get the right of reply. Had to take all the blame 😢

[@bigduphusaj162]

​@@ChifundoBanda good engine builders won't let an engine out that is likely to have issues within a minimum of 50k miles. Also the heavy epoxy primer job on this jag is highly suspicious he's shot it on with a 2.2mm tip and if I remember the vid of it he basically used it as a HB filler coat and final surfacing in one spray. Yeah I don't care who the paint supplier is on that one that's not how it's done. You paint boats that way that have been barrier coated not cars. Basically polly paint plasticoated primer they went with an epoxy primer from a manufacturer that had just got involved in epoxy and knew F-all. That's the truth too and the engine bay was basically done like a spray on filler job. That's gunna crack off within 3yr with heat cycles mark my words. Too much paint thickness for any single coat.

[@jowarrior]

@@ChifundoBandathe funny part is that Charlie was probably behind the camera 😂

[@user-fb9os7hy2y]

Totally agree,the new 'plastic fantastic' stuffs all just blablabla to me, they are all crass, as desirable as standing on a plug.

[@assininecomment1630]

Really, @@jowarrior? I didn't think the camera work was that bad.

[@thegibbonisreal]

Sadly there are people who despite being warned beforehand will insist that 'it was fine before you touched it so it's your fault' and refuse to listen to any other opinion. Well done to Harry for being so reasonable.

[@MARTINA-gc3tq]

Haha……I don’t know what I’ve done but let me sell you all of this new stuff……haha…mug

[@russfoggan4092]

This is my favorite car of all your cars Harry, glad to see it getting the attention it deserves

[@scuderiadeipazzi6968]

100% true gibbon... Sometimes sh.t Happens and you'll never know why.... Anyway, huge conversion, Big job, good decision Harry.

[@shane6115]

Oh Harry just aswell you have loads of money, cause this is going to cost a bomb.

[@Lee012]

I see both sides, if your the customer and it did work before hand you feel let down. But the experience of the man who works on them day in day out should probably take his advice from the start.

[@robsawalker]

Whilst I feel Harry's pain on getting this fuelling sorted, it's always nice to see stuff on the Jag again, it's so gorgeous

[@patb5266]

Damn straight, it's a beautiful machine, even that pesky motor is.

[@rob5944]

Personally I've always loved the series 1, not to impugn this car.

[@mrcaboosevg6089]

XJ Coupe really has to be one of the most beautiful cars ever made

[@frankkemble2103]

I've worked on V12 Jags for many years and have one of my own too and this just doesn't smell right. This seems to me to be a case of cracking a nut with a road roller. The basic premise of a fuel injection system is a pressurised fuel rail where injectors just release the pressure when provided with a 12 volt pulse at the right time. If you have fuel pressure and the pulse timing is right then the system just can't NOT work. A motor that starts progressively to run on fewer cylinders is quite obviously suffering fuel starvation which is usually one of four things, a faulty pump ( very common) , a clogged filter also very common because of silt in the tank) , a failing pressure regulator or a faulty Throttle position sensor. If the car was running okay and then started to misbehave then it's because of a component failure. I've never failed to get a V12 Jag running right and i don't buy this explanation that the system never worked properly because it did and does when maintained just like any other vehicle on the road.

[@nicholasrigg8999]

Harry's chequebook doing a great job supporting the UK tuning and restoration industry!

[@MrEMrC]

Two blokes in an industrial unit, talking about stuff that I probably won't need; and yet there go nearly 24 very enjoyable minutes. Wonderful.

[@grahamp4384]

Still my favourite car in the garage. 👍

[@mmmmmmmmmmmmmmm420]

The spend on this car is eye-watering. I'm of an age that I remember seeing these cars on the road when they were new and more clearly remember how they quickly deteriorated. As a result, I don't have any desire to own one but I admire Harry's determination to get his sorted.

[@Beer_Dad1975]

It'll be super reliable once the modern injection and ignition systems are in it - comparable to a modern car.

[@vicomtedelomagne]

My dad had a 4 door one of the same vintage(6 cylinder) and he kept it for 20 yrs. The only big spend was to the suspension when he had a big operation and didn’t drive it for a year.

[@bigduphusaj162]

​@@Beer_Dad1975 carbs on old jag v12 or constant issues. He's already modernised the fuel supply it doesn't work

[@raytrevor1]

Yes, mate of mine had a V12 back in the 1980s. It was wonderful for 10% of the time and even then a nightmare of problems the rest of the time He couldn't wait to get rid of it.

[@Beer_Dad1975]

@@bigduphusaj162 LOL, have you ever owned a car with multiple carbs? I've only ever had a few twin carb, and they are bad enough, constantly fucking around trying to keep them in tune and balanced, trying to deal with vapor lock when you are pushing the engine in hot conditions, poor lambda leading to terrible performance at altitude etc. Strombergs are terrible, SU's are only slightly better - in the end I always converted to Webbers, which were fairly good, but still not a patch on a modern fuel injection system, and expensive to boot. Now days if I was restoring a car & it was in the budget, for sure I'd go full ECU controlled fuel and ignition. Carbs are old, shit technology that should only be used on small displacement engines for lawn care - OR if you are going for absolute originality - which as I mentioned earlier, is what some people love to do & that's great. Harry didn't convert to a modern system, he did a partial conversion on the ignition and tried to restore the original awful 1970's original fuel injection system - which yeah, by this time in its life is no doubt a lot worse than a set of carbs.

[@professorcalculus5315]

Hats off to Harry for almost single handedly keeping the UK’s V12s on the road, where so many others have given up in flurry of bills and fuel costs!

[@mcashnv]

A Swedish bloke has a nice modern plug & play FI system for Jag V-12's built on Ford parts. Seems to work very nicely. About $4,000 IIRC.

[@chesspiece81]

I hate to see all these headaches because I know how excited you were to get this done. Hopefully you get much improved reliability and some significant power gains.

[@Beer_Dad1975]

Makes so much sense to dump all the terrible old engine management tech for the vastly superior modern systems - as pointed out in the video, so much of the old stuff isn't even available anymore - or you have to make do with poor quality refreshed parts, or even worse quality replicas.

[@willemp6432]

@@Beer_Dad1975 It`s a shame that old plumbing has to go. It looked so beautiful but if it`s not working then...well.

[@Beer_Dad1975]

@@ElliHarper It depends on what you are willing to accept - I grew up in the era of this technology, and worse, where you would hope the damn thing would start in the morning, and on long trips it wasn't unusual to have to pull over and mess around with the points to keep the thing running, or climbing a mountain pass and finding your car running out of puff because it has no way to adjust the air/fuel ratio to deal with high altitude... Not to mention the lack of fuel efficiency. Modern crank timing & sensor driven engine management is something I find amazing - when was the last time you had to worry about your car starting on a cold morning? Or dying on the side of the road on the way to the ski field? Of course if you are a purist - and nothing wrong with that - who enjoys the challenge of keeping an old car running in original condition - then that's a hobby in itself.

[@Beer_Dad1975]

@@ElliHarper I guess the parts just wear out - they might work fine if you don't disturb them & keep air, fuel, oil etc running over them with regular driving - but then you pull them off to rebuild the engine, they end up sitting for months on end (I think Harry mentioned 10 months due to covid) - gaskets dry and harden, diaphragms dry and crack and so on. Often when you pull something old and well used apart, it just won't go back together the same.

[@hughjanus3378]

I have implemented this change on my 85 XJS V12. The poor old Engineers had to “make do” with the technology available at the time to control the timing and fuelling. The modern programmable ECU’s opens vast possibilities for control over the engine management courtesy of the high speed microprocessor’s responding to inputs from modern instrumentation with modern software. The possibilities are immense…and the engine can be configured to run sweetly with full control over all the important parameters. Harry’s gonna be very happy with the result!!!!!

[@garethjudd5840]

My late father used to say, "Every pleasure has its price".

[@waynep343]

Had one of these in the shop. Only six injectors firing. No toggling bank 1 bank 2 with the relay on the firewall. In the trunk the computer harness makes a 90 degree bend. The wires on the outside of that bend were stretched so tight the wires broke in the harness. A previous repair was found. But it was too short and pulled apart again. On an 85 XJC v12. Slow overheat. The 87a terminal on the blue diode relay shaped device to control the aux fan had the insulated quick disconnect miss the terminal completely. 2 two fan switches and the ac compressor control circuit never got thru the diode block to the aux relay.

[@NigelMarston]

I've had an Emerald on 2x Caterhams and a Cerbera - I wouldn't have anything else on a project car now. I love them. I have always felt other systems over-complicate things. I could start my cars on the button, with no throttle feathering, even on a very cold day. And I raced one Caterham and the TVR - I never felt there was anything missing. Yes, I'm a bit of a fanboy of both the ECU and Dave & Karl. Whilst I understand trying to retain the original injection system, once you commit to the new, I bet you felt relieved. It'll take away all the doubts about whether you'll get home (although it doesn't on a TVR but that's because there are so many other "opportunities" there).

[@jsleeio]

Not something truly modern like a Haltech that can use drive-by-wire throttles with all the benefits they convey? Haltech's Nexus R5 can drive all 12 injectors and all 12 coils, unlike the Emerald, and also has modern niceties like proper cruise control and flex-fuel (continuously senses and recalibrates for the ethanol content in fuel, no more switching maps/draining tanks). Frankly the Emerald looks like very poor value for money

[@Escygt]

​@@jsleeio agreed. If I was fitting a standalone to that Jag I'd be wanting dual DBW throttle control and dual widebands. The Emerald seems a poor choice but I noticed Dyno Torque also use them on everything. I assume their tech support is second to none.

[@turbowankel1264]

For similar money you could buy a maxx street that much more modern with more to offer. The emerald seems expensive and outdated by comparison

[@woopimagpie]

@@jsleeio Agreed. They should stop messing about with old basic stuff and just install a Haltech. I suspect it might be because the shop is going with what they know works (as the Emerald appears to), therefore making it a straightforward installation with no learning required for either the shop staff or the cars owner. That is totally understandable, but new tech really is better and it really pays to keep up with it. A fully customisable ECU with all the options can really wake up an old engine, you can tune the bejesus out of it and get it running really sweet, far better than it ever did on the factory setup. Fully customisable ECUs are a legitimate performance part now, so much more than just a "brain" that runs things. The Haltech units are surprisingly inexpensive, and their aftermarket/tuning support is on a level that most businesses can only dream about. They can tune your car from the other side of the world via the internet while it's on the dyno. There's no excuse for not using one really.

[@jsleeio]

@@turbowankel1264 yes most of that $10k will probably be in wiring loom, both making & installing the new loom, and removing the old one. The Emerald itself seems to be relatively cheap, under 900GBP? But it's just so primitive and I don't understand why you'd spend so much fixing a V12 and NOT have full 12-cyl sequential injection. Never heard of the MaxxECU Street but I see it can't do 12cyl sequential either

[@bmanduprit2962]

Harry. I’m sorry your cadding about machine is still poorly. But…. I do love seeing all these people who actually know what they are talking about and are helping to keep alive these machines that make us smile 😊

[@asdreww]

Sounds like a great solution Harry. It's a lot of money though. For anyone wondering if there is a cheaper alternative for the Jag V12, the 5.3 XJS from about 1989 had the 'Marelli' ignition system, which has some modern elements, camshaft sensor, slightly better injectors etc, & it is a whole heap more modern/reliable than the older stuff in the XJS/XJ-C etc & probably not that difficult to fit to an older engine. Jag made loads of XJS for the 1989 model year so should be lots available, & crucially 1989 was still pre-catalytic converter.

[@asdreww]

@@DontCryAboutIt eh? The v12 was used until 1996

[@niux919]

I'm glad Harry is sharing cost with us too. It's quite an eye opening to see what is the actual cost of perfect classic car ownership.

[@S-T-E-V-E]

You're doing all the stuff everybody dreams of doing to their engines Harry! 👍

[@TT_1221]

Fascinating insight to the classic Jag .. Loyalty to the original system has been costly indeed in time and money but looks like it will be incredible when finished. It's been a learning curve for sure.

[@street-level]

The problem which Lucas had in 1970 was producing fuel injectors and a control system with the dynamic range from engine tickover to full chat. It took many years to crack, with help. Hence the original inlet system with four large Stromberg carbs. Remember, no computers or sensors to measure everything then. Mixing and matching systems creates headaches.

[@theouleejit9485]

I worked on these back in the '80's in a Jaguar specialist shop in Canada. We never had any trouble with the injection system (& the boss used to race one). That's why I smiled when the first thing that got dumped was actually the ignition system! That was junk and at one point the boss brought us all T shirts with the pretty green Lucas logo on the front and the words:- "The British drink warm beer because they have Lucas refrigerators!" on the back. ;-) The XJC 12 was my all time favourite I must say.

[@markbennett9787]

I don’t think I’ve ever seen Harry quite so nervous about a project, just hope that they’ve found a solution and he doesn’t have to throw more spondoolies at it.

[@froggy0162]

He's not nervous as such, he's hesitant because he can sense he is being taken for a ride. That mechanic is just doing an upsell, and blaming his inability to properly reassemble what was a working system on the car.

[@verdict1163]

​@@froggy0162 I tend to agree that the problems are user error. Most of these factory systems work just fine. I'm surprised he didn't bring it to Iain Tyrrell.

[@spacemanclips]

@@froggy0162 It's not an upsell. Harry wants an easier life and something that works. This is the way to achieve it.

[@froggy0162]

@@spacemanclips No, he wanted those original and unique parts retained and a working engine. He is being up sold by being told the old stuff cant work, despite it working before it was pulled apart. I call bullshit. A massively expensive and complicated modernisation might yield some performance gains, but it is NOT the only way to make it work. The original components will work if you apply the correct effort and attitude.

[@AB-80X]

I don't see why they couldn't just fit a modern ECU with modern injector drivers, a 60-2 crank trigger and retain the entire intake manifold. People do that all the time.

[@timc924]

Sobering and yet enthralling. The realities of love...yes?: This Jag is destined to become a celebrated and adored feature of your channel, Harry. As I watch from afar, almost perpetually scrapping spare cash to keep my slightly more modest, yet cherished classic fleet going, I can say with my hand on heart and my wallet weeping, that I would not have it any other way and for those of us who watch your video's and avidly follow the restoration editions in particular, we feel your pain but know you'll feel it was worth it when you let that cat out of the cage on those glorious twisty roads around your manor. Best of luck and I recommend a diet of bread and water- my partner leaves a slice and modest glass outside of the shed every now and again, but revels in those weekend trips beside me when I'm not ensconced in fettling one of them. Regards from Australia.

[@thepie4052]

Watching and listening to these specialists is so interesting. Mechanical mindfulness 👌

[@burrow70]

love listening to someone like Tom who really knows his stuff.... brilliant video

[@shanehnorman]

Never ceases to enthrall me when a seasoned professional describes his craft. In this case, that may not involve hand filing or hacksawing components like Ivan Dutton or Allen Millyard, but it was fascinating to learn more about the workings of electronic-era ignition and fuelling.

[@whitesteamerstephens1379]

I seen Allen Millyard and his mad bikes! not heard of Ivan Dutton thus checked him out..love it! Thank you for dropping his name...cheers

[@dublinboxnut7919]

Totally agree I could listen to master craftsmen all day, just like this fine one. 👌

[@classiced1416]

Interesting video. I don't really agree re the unreliability of D-Jet, although I think the Jag system is more complex than the one fitted to Mercedes. It is often unfairly disparaged by garages who do not fully understand it - when new it was the best EFI system in existence. The statement that the MAP is unavailable / not repairable I believe is incorrect, I had a D-Jet MAP rebuilt last year and it made a big improvement to the running of the car. Most the parts can be brought back to spec. At a 12k price point, I would be inclined to seek a second opinion.

[@andoletube]

Agreed. I'd feel a lot more convinced if this bloke could actually articulate what exactly is going wrong. I wouldn't be satisfied with broad statements like "sometimes it works, sometimes it doesn't. Sometimes you fix one thing, then another thing breaks." It's not a scientific discussion. Somebody who really gets it will know what fails and what the remedy is. Or at least be able to articulate it and explain why it's not able to be remedied. The fact that some people have their system working shows there is a gap in understanding between mechanics. The fact that the new system will work brilliantly has nothing to do with why he couldn't get the old system working. And the fact that so many people chime in saying that they couldn't get their's working has nothing to do with it either. The fact that some people can get them working says it all. It comes down to knowledge and skill.

[@jamsstar2010]

Once you have done all the hardware and set all the linkages , it tends to be wiring issue after that Problem is once you have found one broken wire you need to do all of it Not sure which would be cheaper to fix though 🤔

[@alembic1105]

@@andoletube Also agreed, and I've been through this same experience way too many times as well. The original parts work fine for decades and then break down due to old age, then I go to a "specialist" who is really the most prominent person who I can find on Google. They then charge me thousands on replacing a part which either doesn't fix the problem at all, or just as bad, the replacement part only lasts about 2 years when the original lasted 20. But because I'm very reasonable I don't really complain, and I end up paying thousands chasing an issue around, and I always have a nagging feeling in the back of my mind that somewhere there's some old guy in a shed who knows exactly how these things work, and can rebuild them flawlessly for a tiny fraction of the cost. And I always wonder why I can never find those true specialists, and I worry that as they age and retire that their knowledge is being lost to time (or just because they never knew many people in the first place so their knowledge was never spread). And then I'm just left Googling "specialists" to sink thousands of pounds (and loads of time going back and forth) into fixing problems that should be diagnosable and fixable first time. Also why are we paying top money for dodgy second hand parts of "OEM spec" parts which only last a fraction of the time of the genuine parts?

[@ValladolidArde]

@@alembic1105 Hello from the canary islands Alembic, retired motorsport engineer here. Your comment and @classiced1416 are absolutely spot on. You really have to search around to find the old boys that truly understand these systems and that aren't sick of cars and still feel happy to work on them. Normally they are so worn and tired of such a unrewarding job that they simply refuse to work on the things after retirement. So ...I don't want to be mean to this "jag specialist" but I have a feeling he is more of an engine builder specialist rather than a electronics systems or classic injection expert. I say this because it left me wondering when he showed he was reinstalling rebuilt but still medicore 1st generation bosch injectors back on the new emerald setup, bosch inj from this era have ferrous internals that tend to rust because of the ethanol content in "modern" fuels and their spray nozzles are rubbish in atomization capacity. When working on my old classics I replace them with 4th gen injectors that have full stainless steel internals and laser cut micro multi nozzles that do a stunning job and come cheap if you manage to buy them at a breakers, last set for a bmw e23 735i I own cost me just 50quid with a cleaning service done before installation, also treated the metal tank with an ethanol proof resin, installed a ethanol resistan fuel pump and also replaced all the rubber fuel lines with 100% ethanol proof lines that should last a lifetime. So when I heard this chap say he was reinstalling inappropriate 90's injectors for modern fuels I kind of thought he is not a great engine diagnostics kinda guy and more of a engine builder. something tells me the jag fuel pumps are not ethanol proof either and that the fuel tank is probable mild steel too that will rust with ethanol fuels inside it if not treated. So, I'm no expert in old injection systems but when I need to repair the k-jetronic system on a merc 190 16v I own I call an old boy retired from the local mercedes dealer I was lucky to know one day, Mr Jesus Sosa. He pops by from the neighbouring island and works his magic on the car, also teaching me in the process, cars run like a treat after he has dealt with them, He understands the systems intimately and we even repaired an old diaphragm with some special ethanol proof diaphragm material I managed to source online so as to future proof it. You can clearly see Mr Jesus understands each component and manages to explain why they are at fault and how to repair them.... something that didn't come across in this video for a jaguar specialist. The emerald ecu also allows you to use different injector types thanks to the full adaptability of its internal injector drivers, so you wouldn't even need to worry about low or high impedance injectors or installing higher cc injectors that suit the considerable mods this motor has and that make adapting junkyard injectors a walk in the park (for my classics with standard ECUs I must match the exact impedance, cc output, spray pattern and injector body size). I really would have liked harry to go on a jag forum and investigate if other specialists where available for a second opinion and alternate solutions, 10k is A LOT of money and the car looses it's original flair/value considering it had a renowned classic tuner setup installed, it´s gone from a splendid classic super special jewel to a restomod jag.... and i'm afraid its because he truly has not encountered an authentic classic injection specialist. Probably a sublime engine builder, but not a deeply knowledgable classic jaguar specialist.

[@alembic1105]

@@ValladolidArde Wow, you clearly know your stuff. And lots of what you've said really stood out to me, and it really contrasts with what the mechanic in this video was saying. When I read your posts the things that stand out to me are research, diagnose, repair, ethanol proof, rust, modern! These are concepts completely missing in the video. The mechanic in this video felt to me like he just doesn't want to know about any of that, and he's trying to use a sledge hammer to swat a fly. And it's a shame as you say because it was a really sweet setup beforehand anyway, and now it's going to lose a lot of the originality and provenance, and there are still so many blind spots to the solutions proposed. Frankly I wouldn't be surprised if they still have exactly the same problems after doing all the work because of something silly like the fuel pumps anyway!

[@cme2cau]

That old ECU brought back memories. In the early 90s I had a Volvo 164E with D-Jetronic. It worked fine back then as I remember. I don't think that 30 years would have been to kind to it, however!

[@1258-Eckhart]

What lovely cars they were, thanks for reminding me. They were the staple of Soviet top brass. Makes me wonder why Volvo replaced their 3-litre inline 6 with the Douvrin V6 unit. I suppose the V6 shaved about 20 kg off the weight though.

[@cme2cau]

@@1258-Eckhart I traded the 164 on a 760GLE. This was a mistake!

[@neilfairless4589]

When you know it's a keeper like this V12 is, the first drive will tell you it was well worth the cost and wait. Looking forward to an epic road trip soon in this Harry.

[@970357ers]

I believe that with time and environmental pressures, modern ECU upgrades will be viewed the same as disc brake upgrades: essential if you want to enjoy driving safely/responsibly your classic.

[@bramboer727]

Seriously enjoyed this episode. Good humour, and some nicely worded self-mockery! Well done.

[@Lemma01]

I love these problems - those of us with limited budgets always accept we're kicking problems down the road. But to see Harry, with 10 x deeper pockets suffering similar issues somehow makes me feel better about my leaks and splutters... hope this sorts itself out!

[@toguro1009]

That coupe is beautiful at any angle. I have admired them since I was a kid in the 70s. It needs to run as good as it looks. Good luck, Harry,

[@1258-Eckhart]

Me too! 🤩🤩🤩

[@cepheus7850]

Thank you, Harry and Tom, for this great video. Tom's expertise and discussion about the process of the conversion was fun to listen to. I thoroughly enjoy when Harry goes to see all these wonderful specialists keeping good-looking classics on the road with some practical restomods and other enhancements. 👍

[@mrgasman9632]

I can’t wait to see how this runs afterwards

[@oldclassiccarUK]

What a stunning XJC, not sure I'd want all the modern gizmos but I suppose if it gets it running properly then I can see why it'd appeal. Look forward to seeing/hearing the end result 👍

[@ralphmillais5237]

I am still a big fan of carburettors. I love the simplicity, and in my opinion they work so well on most classics for the mileage I do, that I do not regard EFI as worth the bother. I love the Weber DCOE, and on many British cars the good old SU still works very well!

[@oldclassiccarUK]

@@ralphmillais5237 I remember setting up the four Strombergs on a Series 1 XJ12 I owned in the 1990s, a lovely old car that was. I think I'd go down the period many-carb option if it were mine, but there's no denying the efficiency of a modern setup.

[@racketman2u]

@@ralphmillais5237 Can't say I agree at all; the SU, with its moving piston and lack of accelerator pump, is simply awful for throttle response and airflow, which is why racing engines of the day went to Webers. Now they are a good carb but hell to set up for road use with their complex staging. EFI is so superior for tuning that it is a no-brainer. However on british cars like the Morrie Minor where the engines are low power anyway, the SU is fine and easy to set up.

[@ralphmillais5237]

@@racketman2u I can see where you are coming from and do not entirely disagree but I have to push back a little. The SU carb performs better than you suggest, but you are correct the Weber gave better power. I am a massive fan of the Weber/Dellorto DCOE and have used them for years on a variety of engines and whilst many are afraid of them and say they cannot be set up properly I have to say in all modesty that I get DCOEs running so well that I do not consider EFI worth the cost for my purposes. Careful attention needs to be given to the progression phase. However, I have been at it since the 1980s so I have the experience. Having said all this, there is a reason all modern cars are EFI, it is objectively superior, so in this you are undeniably correct, but for me personally it is not so much better that I can be bothered with it. I love Carbs! Best.

[@jamesellsworth9673]

The world needs these master mechanics you interview! The good news is that you can afford BOTH to be a farmer and to maintain such a fine collection of cars. In this case, it is wonderful that you can 'resto-mod' this coupe to be as functional as originally intended.

[@mike_oe]

I'll just quote myself from a year ago, when work on that engine was in process: "I'd go for a full custom engine management system with individual ingnition coils. That old wiring harness, the distributor and the injectors just gives me the creeps..." I've worked on Jaguars since I was 6 years old, my first job was lying in the trunk of my fathers mk2 and banging the fuel pump with a screwdriver when it stalled. When I got older, I transitorised his XJ6 fuel pumps, fixed the SUs and my last job for him was sorting the ignition and piping & wiring nightmare of his V12 XJS.

[@splodge57]

Saw your comment in part 4. You were right.👍 Shame Harry didn't take your advise.

[@ashtonmark24]

I love all the so called experts saying Tom doesn't know what he's talking about (I wonder how many of them have rebuilt such a complex engine). Anyone who actually knows Jags knows how dodgy the V12 could be. I remember admiring a couple of XJs at a local museum and hearing their owner saying how the V12 was a nightmare to keep running well... I used Tom for years when I had my XKR, he's a former Jaguar master technician and really knows his stuff, especially as he also races them. I totally agree with the above and to be fair Harry himself says he should have listened (although I understand his desire to keep it original). For a car that has been mechanically improved/modernised for reliability it makes a lot of sense to sort the engine in this way vs spend ages trying to track a fault and end up either not fixing it or a new one occurring. Reliability is key unless it's an 'original' show car you trailer everywhere... The fact is, some Jaguar design was just crap design/done on a budget and there are better options out there when you have to replace stuff... I'm assuming this is the same/similar engine, but some lovely detail here... www.jagweb.com/aj6eng/djetronic.php

[@yossarian3]

Love this car. Looking forward to seeing it sorted out.

[@keeperlit.leterrip7722]

I had an 84 xjs and I never had a problem with misfiring. It had some things that needed attention and i worked on it myself. Typical maintenance issues like fuel injector hoses needed replaced and ignition amplifier went bad. My ecu went bad causing the oxygen sensors to stop working, It's hard to believe your car has so many issues after all that work you put into it. Expensive fix, but it probably will run much better and the mpg increase is impressive.

[@MagicAyrtonforever]

Twelve individual throttle bodies, job done!

[@leeevernden]

Really enjoyed that one Harry. Also nice to see the AJ16SC making a cameo, such an underrated power unit.

[@moog247]

I really appreciate Harry's journey on his classics, not least the costs! Looking forward to seeing this running.

[@opusgazelle]

These passion project videos are absolutely fascinating Harry. V informative. Not sure if I like these even more than the long road-trip videos.

[@royeady800]

I am sure harry will have a long trip planned after the gremlin are gone, I will be wating for that!

[@chrispowell5258]

Super video. I’ve had full AJ6 Engineering conversion on my XJS for over 20 years. Brilliant. Thanks again

[@peterprice5896]

I feel your frustration harry but I’m sure this man will put it right and you will have a 2 door fire breathing beast 👍

[@jimdee9801]

If at first we dont succeed....love your dilligence for these old flawed masterpieces

[@billholmes3462]

So pleased I kept with a straight 6 in my Coupe. What with £20k for the original engine rebuild and another £14k for the conversion it’s a good job Harry has deep pockets only hope it finally works out for you.

[@martynphillips6646]

This was always Jag ownership and it seems it still is. Mine always spent more time in the workshop than on the road. Best of luck Harry.

[@fransb8543]

I love the jag, too bad to see new content on it at your expense. But it's a thing of beauty. I still think it would look absolutely smashing with a subtle golden coach stripe.

[@davebarron5939]

This will be great, now the Jag will run as beautiful as it looks!

[@ATomRileyA]

Sounds great with the new exhaust, be glad for you when its all up and running again. I think with these older cars fitting more modern injection and ignition is the best thing you can do just makes them so more usable and fun to drive.

[@davidruddick3346]

You can sense Harry’s frustration and gritted teeth through all this video

[@stephenbirds5169]

My dad had an XJ12L, reg. YRC 202M, I loved washing and cleaning it every Sunday plus I could,nt resist a quick spin up and down the road afterwards (to dry it off); great, dangerous thrill when you are just 14. Unfortunately the car spent most of its days at Mann Egertons in Derby being repaired. Huge bills in those days (70,s). Best of luck Harry.

[@alzdeane]

I met Tom a few years ago when I took my XKR to him to quote on some rust repairs... the quote was more than the car's value so I started restoring it myself shortly after. He certainly knows his stuff, and the V12 conversion is very good, just very expensive!

[@danielmarshall4587]

The "Snap-on" and "Castrol" FENDER COVERS very nice and what a lovely video thank you Harry.

[@glynnwright1699]

Such a classy car, I am so pleased that he is taking good care of it. The two Lister XJC I saw in their paint shop were amongst the meanest looking road legal cars I have ever seen.

[@primozkrajcar4144]

Good luck with the upgrade Harry! A gorgeous car that deserves a proper working engine!

[@GuyChapman]

Fantastic vid, Mr. M. Thanks! I learned some stuff, but most especially I like the fact that you show your hand on these jobs. The costs, the benefits, the value you put into your fondness for the specific car.

[@barnabysmith5309]

Those 5.3 V12 engines are a nightmare. I feel for Harry and really respect his determination - true grit. My Jag specialist freely admits he doesn’t know half of what’s going on under the hood of my ‘81 XJS HE - same engine I think - and he is baffled by the injection mechanism…

[@handhwiegman8115]

I also enjoy seeing this XJC on Harry’s channel. The issue of dropping cylinders may have been addressed by Adam on his channel “Living with a Classic” by raising the fuel pressure a bit. That can help extend the useable life of the OEM system. Although the updated FI system with Lambda sensor does return better fuel economy and less maintenance.

[@mawin5899]

I've had a couple of classics with fully sequential ignition and injection with coil on plug ignition. The way they drive after a conversion is like a night and day difference. They drive so well with engine management it is incredible. Apart from the driveability you have more torque across a wider range, more power and much better fuel consumption.

[@MrAndyS]

I can imagine things get quite complicated with 12cyls and carbs most probably wouldn’t even notice there’s a fault just realised it’s injected but you get the point !😊

[@AxLWake]

I'v already said it in a previous video but I'll say it again: this car is my favorite in Harry's collection. Even if he has a very nice collection with quite a few impressive cars.

[@georgebettiol8338]

An interesting video on Jaguar’s D-Jetronic injection system - which was the first generation pulsed injection system developed by Bosch. Essentially, D-Jetronic is the forerunner to the later L-Jetronic injection system that was extensively adopted by numerous OEMs. Troubleshooting a Mercedes 280SE (or 300 as I can’t clearly recall) was my first experience with such a system. The car was running in ‘fits and spurts’ and after an exhausting diagnosis found that the ECU was the root cause. Finding a 2nd hand replacement that was in guaranteed working order was an absolute palaver - as there was nobody at the time refurbishing these ECUs - and expect that the situation has not changed - all made worse by the fact there weren’t many D-Jetronic equipped Mercedes (in relative terms) sold. Notably, Mercedes quickly changed to Bosch K-Jetronic (continuous injection system (CIS) ) in the late 70’s as the CIS system offered better reliability/performance at the time - and most likely cheaper to build. Unless you are an experienced electronics technician or electronics engineer, repairing a D-Jetronic ECU would be an absolute mission - as OEM parts availability is nil and no organisation is investing time and money into refurbishing these. Consequently the solution sought by Harry is the logical choice if performance, reliability and fuel economy is the priority over originality.

[@Juancheros]

Yes the Bosch D-jet ECU had weak drive to the injectors with those series resistors to the PNP transistors in a simple on/off scheme resulting to inconsistent injector opening times between cylinders resulting to practically impossible to repair misfires and uneven unpredictable idle. The solution is an extensive renovation of the ECU to make them like modern 2-step-On signal for each injector. After that a fix for the (4 on the V8 for example) trigger points which easily foul with oil or dirt. Then there's the open loop which CAN be put to closed loop with an external 02 sensor and again significant renovation inside the ECU to interface. After these crazy changes, the analog-based fuel vs temperature vs altitude was never perfect to begin with also drifts with age. Exactly as wtls83 said, this can all be addressed by an electronics engineer (me) with the appropriate skills, jigs and willingness which is generally unlikely to happen. I am surprised Tom Lenthalls said it is a never ending process and I think so too. It was a marvel in its day but time has left it behind. For folks who are in some corner of the world, the D-jet is best kept in a glass case for viewing and not for road use.

[@chadderton]

I'd love to have pockets half as deep as Harry's. I'd throw at cars like confetti. I'm not a fan of the Jag but can really empathise with Harry here. He was so excited to get it back to good health.

[@billkeaveney1526]

Thanks Harry i hope you will love it when it is all done.

[@Punisher9419]

I find a lot of remanufactured stuff isn't up to OEM spec. Shock mounts on my XKR only last about 3 years, original ones lasted about 20 years or so. You need to make you're own polybushes for them if you want them to last a reasonable amount of time. It always kind of bothered me you have to pay VAT on repair labour.

[@alembic1105]

Agreed, this is by far the biggest problem. All the original bits on my XK8 seemed to last about 20 years, and then every new "oem spec" part lasts about 2 years. I would love to be able to actually buy genuine parts, it would be more cost effective in the long run.

[@Punisher9419]

@@alembic1105 I think the OEM shock mounts are just age related because the foam just breaks down with time. It changes colour, hardenes and crumbles. The new ones are just crap. Welsh in the US did a poly bush for the shock mount but those also only lasted a few years, there is a guy on the forums you can send you're old ones to and he will cast a bush inside them and those last a long time apparently but he's in Austrialia I think. There is a market for a poly bush for the shock mount so I hope someone just starts selling drop in parts on Ebay or something.

[@bigduphusaj162]

Buy Japanese stuff. Japanese don't mess about they don't use vinyl or polly based resins they use proper epoxy resin they don't skimp on stuff. I'm not talking about buying a Honda part made in the UK I mean source out the component on the Japanese market and look at who's the high end stuff it's easy it's basically Eurocarparts full of the best gear you can buy once translated so you can see what you are getting. America has decent stuff for old jags as long as its the "made in America" stuff and genuine UK bespoke stuff is good too but youl be paying out your hole for it to be genuine bespoke UK level build. You cannot moan one bit if you fit any ebay part to your classic or restoration project you really can't. In the boat building world you cannot even trust the West Systems 105 you buy, it comes dated from 3-5yr been sold on from a UK boat builder yard at the 3yr mark. Still works but ain't fresh and needs heated to over 60deg to force the crystals back to liquid form. Right so you have the choice of brand new fresh liquids or materials or stuff that's been sold on repeatedly from ebay? And thats just your epoxy for fiberglassing.

[@Punisher9419]

@@bigduphusaj162 Thanks for the advice. Do you have any idea where I could try and find a shock mount that would fit? I wander a different car perhaps uses the same mount?

[@RichardMcLaren]

You pay VAT on everything. The reason it's sometimes, what appears to be, an additional cost over and above a quoted figure, is for commercial enterprises that 'claim back' VAT as a business expense. Tther3s no reason to be uncomfortable about it, you just don't understand it.

[@markaldridge2531]

Harry, I feel your pain old fruit! We have all gone a certain route thinking it better to stay original, especially with the previous upgrades on this car. Sometimes we learn the hard way it is better to listen to the experts who do this day in day out. When it all gets done it will be fantastic, expensive but fantastic. It will also be very rare and unique to you. Little comfort I know, but how many manual V12 coupes out there new or old - now there is a challenge for a comparison right there!

[@rosscopcoltrain8059]

Looking forward to hearing the Coup roar again. It’s a piece of automotive art.

[@joes3461]

Hopefully all of this will fix the injector gremlins! Looking forward to a driving update once its all fixed. 👍

[@SingSurfStrum]

It pleases me greatly that craftsman and enthusiasts keep these wonderful machines alive. The infectious mutual passion and respect restores my faith in human kind given the modern exposure to widespread negativity

[@sresto7943]

I did exactly the same with my project, spent a fortune on the eng and ran it in on std old system, a few cough's later and finaly a tow home, it was out with the old and in with an Emerald, mapping isnt perfect but once warm its a screamer, its all a learning curve, although i didnt send a few sheckles on manifolds though, looking forward to the jag on the rollers.

[@toiyjonson7564]

Great video Harry. Hope this fix the issue and we can see the jag making you happy. Hope to see more road trips with mrs. Metcalfe.

[@performancedownunder5773]

It's been a long and interesting journey with this Jag Harry, thanks for taking us along with you, I've really enjoyed the ride!

[@GeordieAmanda]

Such a beautiful looking car deserves to be running in perfect health. Can't wait to see here running on all 12 cylinders again and roaring down the road 🥰

[@Stephen.C.]

Lucky to find someone so clued up on these old V12s

[@silversuit66]

Wish we had this bloke in Australia. Knows his stuff 👍🏻

[@mrm.486]

This specialist talks a good game. My guess is you will encounter further problems down the line.

[@duggy788]

that old manifold is a thing of beauty would make a lovely display under a glass panel maybe a coffee table type thing ? .

[@clevelandaeromotive]

Classic XJ’s have to be some of the most beautiful cars that ever hit the world’s roads. They also have to be some of the most troubled. Good luck Harry.

[@jrbuch]

Modern ECU technology has come such a long way. Driveability is much improved. You won't regret the new system Harry.

[@pugflyer]

hindsight is always a clear vision.

[@vernonbennettiii3646]

OMG! Makes me glad I sold my '89 XJS V-12 Rouge Edition Coupe when I did (about 27 years ago)!

[@martinmcdonald4207]

I feel really invested in this old beautie. It`s worth every effort possible to get this V12 running to at least 300 bhp. Looking forward to the next report on the old green girl!

[@JB-xd9dr]

Net net, Harry is a savvy man and will have know exactly what the restoration on this could mean. Perhaps a tad over optimistic if he thought there wouldn’t be ongoing issues. It’s a Jag after all.

[@KarelBeelaertsvanBlokland]

Most interesting - Getting old classics with updated fuel/EMS ignition system!

[@michaelh5722]

Hope it all gets sorted in time for a summer road trip!

[@murrieteacher]

I wish I had experts like that in Brisbane Australia. I am 18 months into a chase for a miss in an MGTF 160 that ends up heating the exhaust system (now new and still does it) where the boot liner starts smouldering. Another informative video Harry.

[@nephos100]

Hi Peter. I'm from Brisbane too. I have a 1993 Ford Telstar Ghia that needs attention with a leaky rocker cover gasket and revs too low at start up and while running. Any ideas? Motorama don't seem to have a clue, at least with the low revs.

[@murrieteacher]

@@nephos100 take the cover off and put it on a flat surface and see if it is warped. If it is then that may effect your PCV valve which can cause engine speed. A warped rocker cover will not seal. Hope it is not the head.

[@nephos100]

@@murrieteacher Cheers. I will check it out.

[@anthonywbelcher]

It's nice to keep things in period but having said that you can't beat modern electronics. I've even got electronic ignition on my Austin 7, it made a huge difference to its performance.

[@FeelsDonkMan]

These videos are so good, especially when they highlight the skill good mechanics have. Always so fascinating.

[@lucindafergusonart]

I absolutely love the Jaguar XJ12 coupe what a fantastic car and that one has cool number plate

[@Angus-py6fw]

For the folks having a bit of a pop at Tom Lenthall....some thoughts for your consideration: Harry's objective was an top-notch XJ12 that he can periodically pull out the barn with confidence he could drive it to South of France....without Charlie tagging along with a Landie and a trailer to ensure it gets back home. (he has first-hand experience of that disaster scenario - check-out the recalcitrant Testarossa en-route to Sahara). Tom appears well attuned to his customer's goals and aspirations - during the rebuild he knew Harry is not the type of classic enthusiast who finds their pleasure in weekends heroically spannering away to gain an intimate knowledge of the inherent and recurring failure points of early FI systems (and their reliance on unobtainable spare parts). Go to the vid at 8 minutes in - Tom hits the nail on the head - "I can fix it for you but you will likely just be chasing unreliability..." to which Harry responds "I've absolutely had enough..." Now....about the cost...yes, it's an expensive enhancement...but there are quite a lot of parts involved, plus custom fabrication, labour and then rolling-road set-up...that's quite involving for a V12. The Tom Lenthall website quotes price list for classic Jaguar work at £80+VAT per hour. On that basis, Tom isn't the cheapest classic workshop around but appears to deliver a wealth of experience and sage advice at a rate considerably less than my Merc dealer charges for routine servicing.

[@roytyler4996]

The Jaguar is such a gorgeous car and would be in my top 5 garage. Such a huge shame that even with the amazing professional attention that it is still suffering those huge problems. Good luck with the conversion! Loving the videos and the journey!

[@simoncoe7781]

By far the best car in your collection Harry, you and all involved must be so proud ❤

[@llamamanism]

Oh dear, poor Harry, I could hear and feel his disappointment over this extra big expense. Especially after all the other engine work that’s been done. Once you’ve gone this far though you just have to finish and hope this is the last big bill. (we hope)

[@benclark452]

Just love the XJC. New exhaust sounds fantastic!

[@ThePaulv12]

I live in Australia where the under bonnet temps over summer are insane and apart from the injection harness, the injection system was fine * EXCEPT* for that analogue MAP sensor. I got another one from a 164 Volvo and it ran far better, A/F ratio was in spec and fuel consumption was much better (but still poor compared to an HE in tune). HE's in tune get very reasonable fuel consumption. Despite the Lucas sticker on the OEM MAP sensor, the unit is Bosch. Drill the rivets, open it up and defy me LOL.

[@classiced1416]

Yep indeed. It’s a D-Jet system modified slightly for the V12. It was the best system available in 1970 and better than a lot of the in-house Lucas stuff used until the late 80s by Rover Group. It’s weakness was high temperatures - the fuel would tend to vaporise, but not really a problem in Europe. The MAP sensor is key and the statement in the video that they are rubbish / can’t be rebuilt is complete tosh.

[@TBendez]

WIth a little time, and a whole lot of money, you too can have a sorted manual XJC V12 Jag! Honestly, I'm so glad you're doing this. You clearly love the car, it's great content (not to mention advice) and in the end the car will meet or exceed your expectations!

[@davesclassicgaragetours]

There's an art piece in those parts I'm sure. Another great video. Love these visits to workshops.