Leads, coils, plugs, starters, starting probs etc.
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by HJ2 » Wed 28.07.2021, 11:58
It looks like if the injector is stuck open a bit, after you shut down the engine it leaks a little fuel in the cylinder, drowning it.
When you start, the plug is wet and the cylinder misfires. After the fuel evaporates it slowly starts joining the other 3 cylinders.
I would either have the injectors refurbed as suggested above, or replace them for a fresh set.
If you always do what you always did, you always get what you always got
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HJ2
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by Graaf » Wed 28.07.2021, 12:54
HJ2 wrote:It looks like if the injector is stuck open a bit, after you shut down the engine it leaks a little fuel in the cylinder, drowning it.
When you start, the plug is wet and the cylinder misfires. After the fuel evaporates it slowly starts joining the other 3 cylinders.
I would either have the injectors refurbed as suggested above, or replace them for a fresh set.
Thanks for this but the after shutting down the hot engine. When restarted the misfire does not go away.
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by HJ2 » Wed 28.07.2021, 12:59
Not even after a couple of minutes?
If you always do what you always did, you always get what you always got
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by Graaf » Wed 28.07.2021, 16:41
Nope. When it happened I was about 20mins from home.

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by Simon_P » Sun 01.08.2021, 12:33
It sounds like heat soak. Let it get hot with the fans cycling switch off, leave for 30s, start, switch off leave for a minute start... Repeat 90, 120, etc seconds.
Get it traffic jam hot!
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by Graaf » Sun 01.08.2021, 19:18
I must admit that when the problem initially started it was a very hot day and had been run whilst stationary for the mot. The most recent time it was again a hot day.
I took it out for a good run and got it hot on Friday and it started fine. I then shut it in the garage for 20mins and it started ok. Hope the jet cleaned has worked.
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by Graaf » Mon 02.08.2021, 11:49
If the problem turns out to be ‘heat sink’ehat would the remed6 be.
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by Graaf » Fri 13.08.2021, 16:21
Well I thought that the injection cleaner in the tank had sorted my problem but alas no.
Went out in the car today for a longish run. Left it parked for about half hour and misfire when I restarted it. I seems to be ok if it does get hot but when it does
Simon p suggested heat soak but I’m not sure what to do about that. Any more suggestions or should I just set fire to the car and claim on the insurance?
Thanks
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by TorqueHorse » Fri 13.08.2021, 18:59
I've heard of HT coils shorting out when hot (and creating misfire). Have you tried swapping around the coils?
-Matt N
'91 FED M100 -rolling resto...and come to Salt Lake City, for the very first truly national Lotus Car Club event for the USA: LUG September 24-28, 2026
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by Chas54 » Fri 13.08.2021, 19:24
Or even some dodgy wiring to no.1 injector.
I recently had cause to test my injectors on the bench . A two person job. It gives you a visual idea of the injector spray.
I held the removed injector in a clamp on a lab stand , My wife had a syringe filled with injector cleaner (from an aerosol can) attached by a piece of small tubing to the injector inlet.
She applied the pressure and I splashed 3v from a small torch battery holder onto the two injector terminals. Spray visible and looked convincing.
This test cant be considered anything other than confirming the injector isn't blocked and giving it a bit of a flush.
But my moneys still on the injector wiring . No1 injector has the longest cable exposed to some of the hot areas close to the cylinder head. I noticed mine aren't great and have suffered embrittlement due to heat. They even show signs of previous repairs .The plugs are held to the injectors with a U shaped wire clip to retain them . I lost one but made a new from a paper clip.
When the missfire is there, try waggling the injector plug and waggling the injector cables about to see if it goes away.
I'm battling a high CO at the moment and am considering swapping injectors. Although I did have mine cleaned and tested a couple of years ago.
Don't lose heart , you'll get their in the end.
regards
Charlie
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by Graaf » Sat 14.08.2021, 13:26
Thanks chaps, I’ll have a look at the coils and wiring to the injectors.
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by Graaf » Mon 23.08.2021, 14:53
Simon_P wrote:It sounds like heat soak. Let it get hot with the fans cycling switch off, leave for 30s, start, switch off leave for a minute start... Repeat 90, 120, etc seconds.
Get it traffic jam hot!
Simon
I have tried this. After 1m started fine, after 2min OK, after 5min OK, after 10min misfire!
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by Graaf » Mon 23.08.2021, 15:44
TorqueHorse wrote:I've heard of HT coils shorting out when hot (and creating misfire). Have you tried swapping around the coils?
If it was a coil would that not affect 2 cylinders?
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by Graaf » Sun 05.09.2021, 17:38
I should have posted before now, fitted a new set of injectors and all is now good. Even ticks over at correct rpm.
Thanks for the suggestions.
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