1997 Discovery 1 4 0 High engine idle. Cured!

[@NickBeard-xu1yn]

Had high idle on the 4.0 engine fitted to a car I recently bought. Discovered previous owner had messed around with a new stepper motor and given up - leaving it unplugged and in fixed position - followed through your video and had the same experience as you. Replaced IAC and then throttle position sensor - same result as you - thanks a million for the doing this video! Now have to find out why engine light is still on!! Replacement IAC £16, new TPS £160+ - bought a secondhand TPS from breaker £40. Replaced screws with standard Stainless allen cap screws M4x14mm & M4x20mm.

[@BritannicaRestorations]

If I get one of these on high idle again, I will reset the adaptive values first before swapping parts

[@gazzafloss]

Nice work Mike, hope that chap next door appreciates the amount of work you go to to put all that "treasure" in his yard, we might see it on an archaeology channel sometime in the future.

[@BritannicaRestorations]

That's the plan!

[@bigm383]

I only throw dogshit next door, but it’s vacant bushland!

[@audiophil4946]

I picked up a 98 Disco 4.0 a couple of years ago that had been sitting for 8 years. It's been an interesting challenge, as I new nothing about these before, but I now have a nicely running and pretty solid Disco. I'd love to see more of this one on your channel. It looks too good to be a parts vehicle. Cheers from the Right Coast!

[@BritannicaRestorations]

Unfortunately it is a bit basic underneath and there are no papers with it - and here no papers from the last owner means no transfer of ownership - I knew this and why I bought it cheap

[@BittnerBuddenbrock]

Very glad for your fun and gain with thud Discovery1

[@simondrive4616]

Mike " I don't know what fixed it" Simon "nothing to do with that hammer on the slam panel 😳 "

[@accesszero4803]

Them pliers are spot on ,got a few pairs

[@garrykennedy5484]

I like your approach to these things. Very good troubleshooting. Good on ya mate!

[@BritannicaRestorations]

Glad you enjoyed it

[@chrisgreenwood271]

Good tip on the engineers pliers very handy, just ordered some 👍

[@BritannicaRestorations]

Yes they are!

[@SSSwilliams]

sounds as smooth as silk. I think whip it out and detail it. I bet its perfect inside. Great video.

[@BritannicaRestorations]

Thanks 👍

[@jameskerr5756]

I'd love to see behind next doors fence 😀 Excellent that you got the idle sorted, it sounds fantastic, a wee bit fettling and jobsagoodun. All good to know even although mine is the 3.5.

[@BritannicaRestorations]

Sounds a nice motor to refurbish

[@TheJaimilton]

excellent video again, so jealous though, i have been after a TPS for my 4.6 build, and cannot find one anywhere. everyone i have found has come but a different fit.????

[@BritannicaRestorations]

All 4.0 and 4.6 Gems should be the same - and genuine only The Bosch injection system is different, as is the 14CUX (with distributor)

[@richardl7689]

Good job! I’m really enjoying this series on the Discovery.

[@BritannicaRestorations]

Glad to hear it!

[@silverchief023]

So true on the 4.0 GEMS..Absolutely the most solid reliable V-8 of that era. I have owned em all..3.5 4.0 4.6...TOP HATS are the only cure for the dreaded slipped sleeves ticking.. I have seen a trick .At bottom edge of sleeve...some folks have drilled and bolted the sleeves thru the block.

[@djfisjtik]

I appreciate the GEMS 4.0 content! Got one in my Defender 50th. Mine idles a bit slow at around 500 rpm. Only thing i'm worried about is an intermittent oil light sometimes at a traffic light. Changed the oil to the thicker Valvoline VR1 20W50 as was suggested in an RPI Engineering video. It still lights up sometimes but usually dims quickly after a cold start. Made some long trips recently with massive traffic jams and extreme heat. Other than the oil light I feel comfortable reliability wise. Got a new radiator recently. The temperature gauge is typically a few millimeters left from the middle. I do suspect mine has a slipped liner that most of the time doesn't move. When the knocking sound is there it's very rpm dependent and is more prominent in the lower rpm range when accelerating slowly and goes away with higher rpms. When I hear the sound I avoid it by accelerating a bit quicker. At cruising speed the sound isn't there.

[@BritannicaRestorations]

Get the idle speed up - should be 700 Rpm - you may have to reset the adaptive values or do what I did with the TPS

[@Mr_Jimbo]

I'd be willing to bet if you got the idle up to 7-800 your oil light issues will go away

[@peterjohnson2245]

Good job you hadn't put that alternator over the fence!.. i think you need to run a competition on how many musical references you make over a months worth of video's, closest +a tiebreaker get some form of gift... In the mean time i hope you like jammin too.

[@vincentpoole7588]

Mike. Might help to replace the old carbon canister that forced Jimbo's 'Red Baron' Rangie to spill motor oil ? These get blocked and cause all sort of associated engine oil leaks to ! V.

[@BritannicaRestorations]

I have not come across this

[@davidforbes6250]

What's that song 'Falling in love again'?

[@jamescaron6465]

Those 4.0 were pretty stout engines. the problem with them isn't the motor itself, it is all the stuff hanging off it. That was a job well done and i have a feeling that motor has few more miles left in it, once it gets the externals squared up. Considering it was sitting for so long and you were able to get it going is a testament to its ruggedness.

[@BritannicaRestorations]

It would be a nice one to refurbish - need to find if the block is cracked

[@ianhellyer1473]

That engine is sounding better each time you run it and that's before a service. Did you like the original 3.5? Next door must be a scrap metal merchant; lots of free metal.

[@BritannicaRestorations]

The 3.5 was ok, but no real power - bit thirsty for what you got out of it - and poor oil pumps too!

[@bigronvfr750]

Hi Mike could you put a link for those pliers what a great idea 💡

[@BritannicaRestorations]

www.amazon.ca/Engineer-Neji-saurus-PZ-59-Neji-urus/dp/B00NBSVYOY/?_encoding=UTF8&pd_rd_w=suQRk&content-id=amzn1.sym.b09e9731-f0de-43db-b62a-8954bcec282c&pf_rd_p=b09e9731-f0de-43db-b62a-8954bcec282c&pf_rd_r=BWYYQSWH25Q8K8V25AWE&pd_rd_wg=lfARp&pd_rd_r=417be93e-675d-4886-8a98-700e100565b7&ref_=pd_gw_ci_mcx_mr_hp_atf_m

[@melgregory7339]

Have you got a link (or manufacturer) for those pliers ? Really enjoying these last three videos as they are my level of er, engineering.

[@BritannicaRestorations]

Google: ENGINEER PZ-58 Screw Removal Pliers Extractor Pliers

[@melgregory7339]

@@BritannicaRestorations Thanks

[@dieselhatz4247]

@@melgregory7339 I’ve got a set for work and home, amazing pliers. The metal is hard, and the blades sharp. Anything by Engineer is quality, just ensure it is made in Jay-a-pan.

[@eggy1962]

Noisy back end….i got one of those ( not car related)….

[@terrybreeze6070]

Hi Mike I have a 4.0 gems in a 50th Defender, I had starting running problems, it was a faulty ECU so replaced it with a Mark Adams chipped replacement ECU and now its amazing runs cooler and has better mid range, only trouble is it needs a bit of throttle in the cold weather to start and warm up a little before driving or it cuts out, has new TPS and values all checked and set by top Land Rover mechanic , but still has a cold start idle issue in the winter months , no problems in summer, any advise?. cheers Terry

[@BritannicaRestorations]

Could be the temperature sensor near the thermostat

[@terrybreeze6070]

@@BritannicaRestorations Cheers Mike I’ll get it checked. Love your videos

[@Reaper4367]

G'day Mike, awesome job cobber. If i may... here in Aus, we never got the 4.0 in the D1's. Only the 3.9. The 4.0 came out with the D2. Could you please explain what differences there are betwixt the 3.9 and the 4.0. Muchly appreciated. Cheers for sharing.

[@raygale4198]

If I have it right the 3.9 was a progression of the original 3.5 Buick motor. The 4.0 was a new platform. I could be completely wrong but.

[@Reaper4367]

@@raygale4198 a new platform, ok, nice. I wonder if that included block castings?

[@erictyrrell3560]

4.0 was the same displacement as the 3.9. The change was moving from 14CUX to GEMS engine management system.

[@BritannicaRestorations]

The 3.9 was a Lucas 14CUX controlled engine with a distributor The 4.0 was the same size (just renamed it to make a difference) however it was a GEMS controlled unit, no distributor, but a coil pack was fitted, the crank was cross bolted - that meant there were bolts going in from the side of the engine as well as vertical, giving it more strength

[@grahameroberts8109]

Does next door need a ladder to climb over the pile of junk thrown over all these years? Good job on the Disco motor. Now start on the rusty bits. Hmmm 🤔🤪👍🏻🙏🦘

[@BritannicaRestorations]

Nope!

[@DuncanMargetts]

Hahahah that soft spot joke.. I laughed, heartily.. thanks :)

[@BritannicaRestorations]

Glad you liked it!

[@axelboldt5101]

this one would be a car for me!!!

[@patrickjobling8676]

I say squadron leader..excellent results what .. jolly good carryon pip pips 😁

[@BritannicaRestorations]

Thanks 👍

[@antonionunes998]

Are you really going to scrap the car? It seems in good enough condition to deserve a cheap restoration.

[@BritannicaRestorations]

Yeap! Parts only - will need a full inspection to put it on the road and not worth is

[@boromickfc]

Time to take it up the hill🤣

[@BritannicaRestorations]

Spoiler - the shift cable was so rusty it snapped!

[@devilsadvocate1218]

Mike, it aint broke, dont fix it

[@jeffnations6649]

Mas sensor

[@dannydavis1964]

Better watch the man next door hasn't got a dog because he might start throwing dogs eggs back over your side thanks Danny

[@BritannicaRestorations]

lol!

[@Ankeneering]

Like a real internet idiot I’m going to guess the cause of the high idle without even watching the video. Anytime I’ve ever started a d1 4.0 that’s been sitting it has to “re-learn” where base idle is. I drive it around for an hour or so and that seems to fix it.