Disappointing Ignition Upgrades - Good Idea, Bad Results - Jaguar XJ6

Today I replaced all the ignition components on the Series I Jaguar XJ6 while doing a dyno test between each component to see how the replacement affected the car.
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This Week With Cars - Episode 0090

[@mattp4806]

This is the car I’ve been most looking forward to an update for!

[@jonswinfield9336]

I’m really interested in the progress of this Jaguar and would like to see more

[@Millmiglia001]

Put in a new contactless ignition set from Sparkrite. It's what i did to my 1975 Xj6 C and it transformed the engine response and i have NEVER have never had ANY problems with my ignition system since

[@floribertosousa2251]

Hi Steve,..great video again on the Jaguar XJ6. Please do continue with videos on upgrades of this beautiful Jaguar XJ6. Great job,...thanks.

[@edsalerno2790]

I too think part is in the advance possible the springs on the weights or stuck weights plus the distrubtor bushing is probably well worn needing replaced. I don't know if the Jag has a vapor tank but it could be full of dirt too. Coolant temp senor could be bad too. Now we are all curios to see what fixes the Jag!

[@pdterre5496]

Very interesting. A scientific approach on the old XJ.

[@DogsInFremont]

This was really informative . It is also good to hear from someone as experienced as you are, that sometimes things don’t work out the way you expected. Thank you for taking us on your journey.

[@stevestone4346]

I think you're right about the fuelling. I'd ditch the points in favour of electronic ignition, preferably a 123 system. Love the xj6.

[@richardporter6201]

I put a 123 distributor in my TR6. Clear improvement.

[@gazzafloss]

Plugs colour indicated lean mixture from what I could see Steve, I ran an E type from the same era as that XJ for 15 years and never had any problems with the old original points and coil ignition components. I'm keen to see the next installment of this car tuning.

[@steves4639]

I had a couple instances where I was sure the problem was ignition, but it was a clogged fuel filter. 9 times out of 10 its ignition, but as long as the timing is advancing through the revs, the fuel system is the next stop. Still, might be of benefit to pull the dizzy and check the bushings and breaker plate rotation. the first XJ is one of my favs, so def enjoying this series, although its hard to get past my jealousy!

[@dr.leftfield9566]

Go for it Steve. Apart from fuel and carbs i'm at a loss. For a mark 1 xj it's in good shape and getting rarer and you are an excellent surgeon what's not to like?.

[@Mechanical_piano]

I really want to see a new episode on this jaguar! very beautiful car, it’s a pity that it’s still very sick

[@bajabell]

Just rebuilt the Stromberg's on my 1972 V8 Range Rover and it really made a BIG difference ....... May help with the XJ6 ....... Love the car, my Dad had a Daimler Double Six Coupe back in the 1970's ...... Have always loved them ...... Good Luck , Cheers. Richard

[@theoriginalracingsnake]

Really want to see the latest on this. That is the best colour for one of these early cars. Beautiful. It'd be great to see the car making proper power again. Please do another episode!

[@stevepearce6689]

Squadron Blue is nice too

[@curmudgeon1933]

Excellent series and interesting to see the incremental changes and dyno results each time. I'm amazed at the condition of these old classics you keep finding. I'm sure you are paying good money for them as they're getting harder and harder to find in this kind of original, unrestored state.

[@Tasteslikepetrol]

This is a great series and I'm looking forward to seeing what actually fixes the issue. 40hp is just crazy low, I'm amazed it runs as well as it does making so little power.

[@dennislancet]

If you can access one get a dwell meter to set the contact breaker points gap to perfection, also fit new needles & jets to the stromberg carbs, suggest that you fit new diaphragms while you have the carbs stripped down as they do fail with age, Happy tuning !!!

[@thedoublesuser]

I saw the previous video about this jaguar and I was really looking forward to the continuation. This was again a really great video, repairing a beautiful classic car step by step. Keep recording the progress !

[@sunalp2]

I had a 1961 MKII. I lifted the bonnet (hood) in the dark one night to see if there was any leak from the plug leads that sat in between the cams. It was like a spectacular light show, with sparks going every where. I believe the leads should be running through a tube that is suspended by the head bolts on one side.

[@cleanmachine08]

Great video and excited to see more updates on this car. Today I purchased my first Jag, a Series 2 XJ6. Will probably be on a similar journey with it as you are going through now.

[@nabilm2941]

Hope you make more frequent video updates on this XJ.

[@TybeeHandyman]

Really like your methodical approach. I second the comments on checking the ignition advance - both the weights and the vacuum.

[@ThePaulv12]

I had a SII V12 and the distributor in that is in a diabolical position also. It had a well known US brand optical pickup and electronic box. It failed twice. Turns out the upgrade was a downgrade. What I ended up doing was I converted the stock dizzy to reluctor and pickup from an HE V12 by building one distributor from two - an HE dizzy and the pre HE dizzy in it. I didn't know at the time if it was possible actually, but yeah it is. I used the 'Lucas' HE control box. It is not in any way Lucas as it has an off the shelf GM HEI module inside it. For good luck I replaced that module. Put it all together with the twin early type HE coils (firing and non firing) and I could not believe the difference. The starting, esp the hot starting the idling and the top end RPM was so improved it was utterly amazing. It must've picked up 100hp! I took the injectors out after that I was so impressed and the spray patterns were all over the place, so I refitted them and replaced the fuel pump and filter just because I could. It became imperceptible the idle and that smoothness! I hit an escaped farm animal at slow speed and it did so much damage to it that it was uneconomical to repair. The animal fared far better than the car. It rolled on the hood into the A pillar and just walked off as if nothing happened lol. Screen, hood, grill, bumper, front fender and it weight of it pushed the radiator support panel and the radiator down about 3 inches and the engine fan deflected into the radiator. It was like a slow motion crash. Even one of the intake manifolds got cracked. Effing farmers. I now have a 1980 SIII V12.

[@timbre7999]

yes please more videos on this gorgeous XJ6. Hunting for the source of a persisting issue can be very frustrating, I know. And quite a few new parts go on an engine that doesn't perform optimally but eventually it should pay off

[@ggeimer]

I replaced my ignition on my TR7 with an Alison electronic optical system. The reason was I put an ‘80 engine in a ‘77 mint California body and the Lucas systems were different. It paid off in being able to drive for a week daytime without an alternator It also worked at night when I tuned the lights on for a moment snd switched back to parking lights and drove 8 miles home with less than 5v on the battery. Alison ignition works y to around 3.5v and still gives a 10,000 volt spark!

[@jeffharrison5265]

Great info!! I'm doing a restoration on a 1972 XJ6 and will be installing a Pertronix dizzy with matching coil. Keep up the XJ update please.

[@Dave-in-France]

Hi Steve, it's really great to see a Series 1 Jaguar XJ being brought back to life, can't wait to see how much power you end up getting back. Here's a couple of thoughts of things to check : 1. Fuel pump operation and pressure at the carbs; 2. Crankcase breather system, check for blockages. Dave

[@scottparis6355]

Looking forward to the next episode on this car!

[@crispinallen5207]

Excellent work, i like your methodical approach. The original rotor arm is a rev limiting rotor arm, this might explain why it wont rev very high. The max distributor revs should be stamped on the outer ring. Also the distributor looks like it is missing some parts, like the micro adjuster wheel. I cant wait for the next update.

[@graemelliott3942]

Yes keep working on the Jag please. Check the compression. Change fuel filter then dyno test, fuel pump then dyno again finally rebuild carbs then dyno. After check valve clearances. Adjust if needed and dyno.

[@graemelliott3942]

Doctor MENGELE you’re right. It’s basically free to check valves and do a compression test. In the end I bet is a fuel starvation issue. No power over 3K rpms and only is getting 40hp @ the rear wheel. Should be getting like 120-140 hp at over 5K rpm🏁

[@genemccormick3935]

You did a real good job. Engine sounds great thanks to those 7 main bearings. Looking forward to your carb tuning.

[@erikhilsinger9421]

Is there an aftermarket electronic points replacement? For German cars you can get Pertronix and compufire modules that replace the points and condenser. The other ignition item might be a multispark unit, which is usually overkill but looks cool. Definitely think that upgraded fuel pumps, filter, and maybe cleaning out the tanks could help. Fun cars! Enjoying the videos!

[@caseytailfly]

There are probably many small problems here and everything you changed was worthwhile. Wear in the distributor can definitely cause erratic timing at higher rpm and break up. That should be pulled and rebuilt or replaced imo. At a minimum verify that the advance moves freely and the springs are in place.

[@stevenlea4500]

Hi Steve, o/haul those Stromberg CD's, replace the diaphragms, they will have lost all of their flexibility and won't control the piston/needle for proper air/fuel ratio. New fuel filter, fresh high octane fuel. Reset your points with a dwell meter. All of this provided it's mechanically okay. All the best from Australia.

[@mescko]

Steve please check the secondary throttle inside the manifold. I suspect it is disconnected or misadjusted. It could be partially or even mostly blocking airflow.

[@ThisWeekWithCars]

I will check!

[@quantumtime6883]

Love that old Jag, great interior. The horsepower seems quite deficient. Possibly do compression or leak down test on the cylinders.

[@Kleinbissendorf]

Absolutely dump the Lucas distributor and go with a Petronix or 123. Check for vacuum leaks on the shafts using raw propane. Any increase in idle will be indicative of problems. Balance your carbs and make sure the linkages move both butterflies equally. Give us a wet and dry compression check as you might need a valve adjustment or have worn rings. Run some Sea foam and BG44k directly into a vacuum line. Those products really clean out crud and you'll see smoke for awhile as they work.

[@MichaelAmster]

Just a thought. Is it a mechanical advance distributor? Could the springs be worn, old or the mechanism sticky?

[@rhiantaylor3446]

@Sean m Best to check timing at higher rpm too, quite separate from the vacuum timing variation. I would have twisted the rotor arm to check for free movement and possibly looked to see movement to the red timing mark to do this check but was not mentioned.

[@AndyMarsh]

@Sean m I could see that.. If the distributor is stuck and the timing is not changing from initial it's really going to struggle.

[@lrcb40]

I think it's a vacuum advance, so a) check the vacuum tube hasn't got a leak or collapsed - reducing the vacuum at higher engine speeds and b) that the base plate of the distributor is moving. Any rubber hose on a vehicle this age is automatically suspect IMHO

[@eddybetanya]

I changed the fuel filter on my volvo s80, the difference in performance was dramatic. You got two fuel filters, new ones may help.

[@eddybetanya]

Years ago my mate had an S type Jag, his fuel pumps worked but were very lazy, I'm sure he had to change them.

[@brwlegge]

Takes me back to my MG days playing with the ignition of course without the dyno!

[@ianhillsman7777]

Yes, Steve, please keep us posted!

[@u.h.johansen803]

Great video despite not showing what you hoped for. Suggest Fuel and Air next, with dyno run in between each - just like in this video.

[@MrDemonchild71]

It sounds like it's sorta got breathing problems. May be the exhaust is a bit blocked or the wrong muffler. It could even be a bit crushed. That's just what I'm thinking. It should have better gains from what you changed from what they were, especially those leads. Can't wait for next video, I really like them

[@ThisWeekWithCars]

This car has catalytic converters my thought has been they might be clogged.

[@paulsteele6120]

I can only offer the experience with my 1970 MG B, the distributor had been given my a lot of strife and I could not get a steady readout with my timing light. Bought a 1-2-3 electronic distributor and new leads, plugs. The difference was between chalk and cheese, the Lucas (and they are not called The Prince of Darkness for nothing) distributor was giving a trace all over the place , but when the 123 was fitted the graphs where clear and steady. I think fitting all the rest of the gear was a good idea anyway

[@johndavey72]

Steve. That engine sounds so sweet , even under load. And the way the rear drops when applying power tells me there's nothing inherently wrong . It must be making more than the dyno indicates. The only thing l noticed was she sounded lumpy when you checking the timing. I would remove all the smog gear (and probably the air con) swap the Strombergs for S.U's , and then you'd have a Jauar that drives like it should. Next time your in England drive an early one and you will be impressed and take the opportunity to get S/hand carbs.Sounds obvious but l'm sure your aware that water used to get into the tanks. I expect you drained the tanks and put fresh fuel for starters. Very nice looking car. I still miss mine from 40+ years back and the Series 2 had smaller carbs and really struggled to get up and go.

[@lesleysmith5623]

On my BMW R80 with Bing carbs I had same problem i.e. wouldn’t rev past 3500/4000. Problem was worn needles and jets. Difficult to tell just by looking at them. Replaced them. All back to normal.

[@cliffordkiehl3959]

Taking it step by step was very interesting. Want to see the fuel system results.

[@gggrumpy1]

I'd love to see an update on this Jag.

[@adventureswithmichael6589]

You could try spraying a very fine mist of water into the carburetors to give the inside of the cylinders a good steam clean. Another idea I have is maybe installing trumpets on the carburetors so the airflow smooths out and provides better attermisation which improves combustion.

[@zw5509]

My favorite Saloon car Jaguar is the earlier Mark 10 version. Wonderful lines.

[@henkvanlaere4712]

Nice to see and learn, maybe a problem with the type of fuel, leaded or unleaded? Carburator doesn't work correct or pump issue? I don't know, I'm enjoying your working step by step...I'm not an expert, love your working method...great...

[@unclerick8224]

These cars have a classic look to them that is timeless. Even though you didn't get any increase in HP, the engine does sound good.

[@johnmoruzzi7236]

Nice update although what you did isn't really an upgrade, more of a refresh. Hope you find your power and revs ! The XK engine cylinder numbering follows the convention of aero engines, the designers based it on wartime engine techniques and technology which is why it was so advanced at the time.

[@EdwinNew]

Four possibilities; either the advance mechanism may not be working correctly, or the shaft bearings have too much free play, or excessive wear on the cam lobes, or bad wiring on the distributor low-tension circuit. But it could also be the fuel pump, filter or damaged fuel lines. Or blocked high speed jets in the carburettors, or an air leak on the intake manifold(s). Or...

[@Omegaman1969]

I would fit an electronic style distributor , preferably a programmable one . Also check the TDC by removing the spark plug and check the actual piston is at TDC.. check all cylinder compression making sure you have the throttle wide open when testing . Once that has all checked out see what air fuel ratio you get at wide open throttle maximum load ...you want it around 12.5:1 . Try 30 deg total maximum advance and move it a few degrees either way to see what gives best torque.

[@jjjcmo]

Check for vacuum leaks before trying anything else. The hoses and fittings are likely very elderly. When I restored my TR6 fixing the vacuum leaks made a noticeable difference.

[@sjones1974]

Looking forward to the next update.

[@ZelosZelo]

looks to me like an air flow issue. The exhaust seems restricted a little, and it is multiplied as the rpm's increase.

[@philelliott5327]

Split/perished diaphragm in the Stromberg carbs, it is running lean. I would also chuck the points and condensor in the bin and fit a contactless ignition system and a new GT40 coil.

[@MichaelSmith-ne3kj]

Thinking about buying one of these - mind you it is running. That being said I’ve learned so much from watching this series… not sure I’ve got what it takes to actually pull the trigger and make the purchase!

[@smckelvey1959]

If you read this Steve replace the earth strap or at lest clean up where it bolts on ...in fact add a thicker new one from engine to body....i suspect corrosion as crept in and you may have an earthing issue....

[@izzystdln]

How’s the 1971 Jaguar XJ6 ? Any updates ? Maybe a new and upgraded camshaft that would open the valves a bit more. I would like to see more on it. Thank you.

[@ernieleithes6545]

Steve in england we had the Su carbs which in my opinion were better i once worked on a american import jag i took all the emision equipment of it ended with a box of junk after that came of the car flew . I like to gap new points at 16 thou so whe the heal wears initialy the gap closes a few thou , i also think a electronic ignition would help also these are high comp engines they need good high octane fuel.

[@jjmac3561]

You should clean the surface of the points before you fit them, plus put a little grease behind the leading edge of the plastic heel that sits against the cam. Did you check the mechanical and vacuum advance system were working? While it's unlikely that they would be the main cause of it producing such low power outputs they should be thoroughly checked and fixed before moving into the carbs. With such low power output it's a wonder it manages to move the car around at any reasonable speed and degree of acceleration. Best to buy a set of diaphragms for the carbs in advance, or find some 2 inch SU carbs instead.

[@SpkStephen]

Very interesting! Please continue!!!

[@lewisstallings5485]

Happy to see more videos on the jag! Although, I do really enjoy all of the videos you do!!!😃👍🏻

[@jameseastwood4984]

Keep going this is going to be interesting when you find the cause.

[@tabsqc]

I suggest you check the advance inside the distributor and have the dwell angles checked at the same time.

[@silverainbow123456]

Hi - was hoping to see the next instalment after you sorting out the carburettors

[@JonDingle]

I love the car and always wanted a Series 1, had a few Series 2 and one Series 3 V12. I believe the best idea would have been to go for electronic ignition. Part of the reason the Dissy is hard to access is because the XK wasn't designed for that car and it was designed back in or around the late 1940's to go into the XK120 sports car. I would also replace the AED with a manual choke conversion. It may be a good idea to cherck and clean the Earth/ground connections of the car. Judging by the spark plugs, the bores are very good and fuel mixture is spot on.

[@markstott6091]

There is no AED on this car, it has a manual choke.

[@JonDingle]

@@markstott6091 I can see that now. Originally it would have had one. The AED soon went unreliable and gave starting problems. The manual choke conversion is far better.

[@robgclarkson]

just don't stop until this car is running better than new!

[@thechiefengineer5886]

When are we getting to the fuel system ? Im courious to see if it helps .

[@houseonpleasantstreet9774]

I absolutely love this car. Glad you showed it again. Carb issue?

[@retrorestore]

Vacuum advance weights in the bottom of the distributor will be seized. Remove the distributor and free them up and you'll get your power back.

[@davidhayes7646]

The plugs look lean. My Jag is stroppy unless it's a little rich. Check pumps also, they will happily supply fuel to get you up and driving, but not enough for any fun!

[@hermannwissemberg9192]

Hi, >>>Carbon cleaning descaling with hydrogen hho... The Jaguar XJ6 has several known issues with its fuel, mechanical and electrical systems. Most of these problems resulted in recalls for the vehicle in the 1980s and 1990s. Fortunately, the manufacturer of this luxury sedan has come up with several fixes to address concerns about this vehicle's safety and function.

[@grizgut1]

Really want to see this Jaguar purring again 👍. Nearly all the ones in the UK have rusted to pieces and died.

[@leongustavson8746]

Also check fuel filter is not restricting fuel. If ok, check carb float level, carb breather vent. Distributor vacuum advance diaphragm is it working?

[@jamesw5719]

Engine compression test show anything? Oil levels in the SU carbs too high/too low? Fuel filter renewed? If so, does it have two (one near the tanks, one near the carbs?

[@_zzpza]

If it's not ignition or timing, I would check compression and assuming it's ok them move on to checking fuel delivery. Amazing it runs to smoothly whilst being down so much on power.

[@ThisWeekWithCars]

It’s not necessary down on power. At those rpms it may be making proper power for the first couple thousand RPM. It would probably have peak power between 4500-5000 so having 40 at 1500 is reasonable.

[@daveshongkongchinachannel]

Great series and love the methodical approach. Amazed the car produces so little power. I'm no expert but maybe a compression test on each cylinder might reveal some useful information.

[@sambennett3482]

Hi Steve. Thought you would have, with the amount of vintage cars you have. Hope you find more soon,,👍

[@davidwarr8600]

I have a 74 XJ6 so I am following this closely.

[@JourneymanRandy]

It has to be a fuel issue. Looking forward to the next episode

[@mickspencer4171]

You could try rebuilding the carbs and checking for vacuum leaks

[@BenPortmanlewes]

Is the vacuum advance diaphragm fecked?

[@matthewjenkins1161]

Have you replaced the rubber diaphragms yet in the Stromberg carbs? Tiniest pinholes can cause lots of trouble and they only last 5 or 6 years from experience. That experience is from the 80s and 90s, and with alcohol in today's fuels, that would be my first items to change out.

[@matthewjenkins1161]

Oh and check timing moves appropriately as revs increase, not just that it is spot on idling. Mechanical advance can seize and vacuum advance diaphragm may be split.

[@andrewallen9993]

The Lucas points and condenser ignition system on these cars is known to work superbly even after 50 years!

[@Gary-g3q]

Yes more content please

[@josephwarren3498]

I may have missed it, but while the plugs were out did he do a compression check, wet and otherwise?

[@ZaphodsPlanet]

Is there a vacuum advance on the distributor? I see one in the video or what looks like it. Anyway, did you check to see if that's working? .I'd guess that's your problem.

[@mikego18753]

Those old plugs looked about right. cheers. p.s. yes,more please.

[@johnlockhart5889]

Looking forward to the next video on this. I wonder if there may be an issue with mouse nests restricting the exhaust. You did blow some crap out of the exhaust when you first fired it up.

[@lawrencehomer5682]

Please keep going pal. Looking forward to the next episode

[@OhioPeteS2k]

I’d like to see what you’d do in adjusting the carbs. I replaced the ignition system in my Sprite last year and adjusted the carbs to best I could and I still have a low rpm misfire.

[@SB-vb8ch]

Why do you think it's ignition? Strombergs are notorious for diaphragm issues....the ignition side needed doing anyway but carbs & making sure the exhaust isn't full of acorns/collapsed would be wise to look into

[@timgoodman-surman3274]

Compression test should really be your first check. If the compressions are down then you're not going to get any horsepower back until you sort that. Throwing parts at something is an expensive way to fix it. Check your fundamentals first. Nice car though. Good luck.

[@steenlassen5718]

Timing advance. Maybe the connection between the manifold and the distributer is broken. It won't go past 3.500 rpm as you say?

[@jonswinfield9336]

Hi Steve what’s happening with the 1971 jaguar xj6? Can you give us an update?

[@peteredwards9147]

You need to check and if necessary reshim the cams, adjust the timing and then adjust the points with a Dwell meter, in that order. Trust me, the inlet valves can be shimed bit tight and the exhaust valves just abit loose, and add a few PSI to the back tyres to skate the back round on corners, best get away car going.

[@paulbrett8705]

Hey Steve, would love to know if you're still working on the XJ?? Great videos and give me hope and motivation:) I'm about to start the process of trying to get my Dad's XJ Series II running again.