free hit
counters
misfire engine cuts out - Engine/Ancilliaries - The Lotus Forums Jump to content
andy b

misfire engine cuts out

Recommended Posts

I have run the turbo with a sick engine for a few runs (Low compression on 2 pots) just to try it all before pulling the motor. when i put it on the road i went for a run to shepton mallet about 80 mile round trip it ran great ok smoke when the turbo was on full boost but i expected that. But no over heating no misfire pulled well.

I went to the pub with the wife here first run out i went about 15mile fine. then a misfire started and about a mile later cut out and would not start. I had a nose about  and retried it fired up fine (as usual when it stopped it was on a double bend with double white lines in the middle LOL.)

pulled away to find a safer place to break down. but it ran fine turned around and head for home, WE got 4mile misfire and cut out. 5mins later start up went about another 2 mile had to pull onto a lay by.

the next hop running fine fuel warning light came on gauge went to zero that got my attention thought massive fuel leak. pulled over gave it a good look over nope no fuel  spill. turned on the ign all back to normal. next hop was 12mile running at 50/60mph no heavy throttle use just steady.

Made it to a roundabout tick over fine made it to my drive and it cut out spun it on the starter motor in first to get it parked up so the missus could get here car out to get fish & chips LOL. started it up next morning all fine revving well no misfire.

I can't make my mind up weather to run it to identify the fault or pull the engine and fix that first she is out of tax the end of this month. The main thing was we got home.

Ps we had several toots and waves when it was running people do love em.

andy b 

pps I am running the later constant energy system on this car.

Share this post


Link to post
Share on other sites

Upgrade today to remove Google ads and support TLF.

Not a very nice problem!

 

Maybe the loss of fuel gauge is related. A disconnect in the main feed from the ignition switch would cut out the ignition system and the gauge (and a lot more). 

 

As the problem seems to go away by simply re-starting, the actual ignition switch might be a suspect? 

 

Might be worth checking the wiring from battery to ignition switch and from there to the ignition, and fuse box.

Share this post


Link to post
Share on other sites

I would try to get to the bottom of this problem before removing the engine. Sounds like an electrical gremlin but could be a fuel issue. Blockage or old fuel pump. If you havent I would replace the fuel pump as they are only about £40.00 easy to do and if they dont have quite enough umphh can give you all sorts of bother.

 

Buddsy

Share this post


Link to post
Share on other sites

ALWAYS do the diagnosis before anything else!! Pulling the engine out is useless, as it isn't going to tell you anything. You need to have the engine in an operational position to find the fault and confirm that it is fixed once you have. Taking it out is a significant effort and you are quite likely to find nothing wrong with it, the fault lying in the car electrics or associated systems. As has been said, fuel gauge failure is a pointer to an electrical problem. When it cuts out next time, check to see if you have any sparks..don't just try to start up, detach a plug lead and use an old plug to inspect the spark visually. Then work back through the ignition system if you haven't got sparks....

I'd make sure that this fault was diagnosed and mended before I pulled the engine, even if you are going to do a complete rebuild for the low compression problem.

  • Like 1

Share this post


Link to post
Share on other sites

Thanks chaps may put a tool kit in and take it for a last run to try and identify the problem the engine has to come out as there is only 50psi on 2 pots done it all properly engine warm full gas it is amazing it runs as sweet as it does when running and it pulls hard.

in stealth mode blue haze LOL.

I shall have to get my head around it and sort before pulling the motor will keep you informed.

andy b

Share this post


Link to post
Share on other sites

Definitely +1 for John's suggestion. You will disconnect a bunch of stuff removing the engine. Make it run beforehand you will just enjoy it sooner when the engine is back in!

Share this post


Link to post
Share on other sites

My bet is on electrical, the tell being the gauge going to 0. I can't think of any way an issue with the motor could cause that, but hey anythings possible. I would troubleshoot in situ until its resolved. You'd be mighty annoyed to pull the lump out fix it all up and not be able to start it later because of an electrical fault thats completely unrelated to your engine rebuild.

Share this post


Link to post
Share on other sites

Another vote for fix first, if you do a full engine rebuild, running it in with this fault would be most irritating.

Share this post


Link to post
Share on other sites

I have a similar issue.  Miss fire when accelerating hard but seem to run fine when driving gently.  I do also occasionally get the fuel gauge drop to zero but also the temp gauge.  A knock on the dial usually solves it.  I have not noticed though any connection with miss fire and gauges dropping out.  Not saying there isn't though.  Need to start investigating.

Keep us posted Andy on your progress.

Share this post


Link to post
Share on other sites

Both the fuel gauge and the temperature gauge get their electrical supply via a very crude voltage regulator, behind the instrument panel....so if both are malfunctioning together, it could be this that is at fault. Or....the supply to it is failing, and that could cause the misfire too. If it's just the gauges, then it's probably the regulator...if you replace it, use an electronic one....more reliable.

Share this post


Link to post
Share on other sites

I have been out in the turbo for 2hours running up and down a bypass road plenty of roundabouts to pull hard out of. i set up my timing light in the boot and gafa taped it so i could see it in the rear view mirror. it ran fine ok plenty of oil being burnt when the turbo was working hard. i ran it up to hot before i went for about 30 mins. so i am none the wiser

when i got back i took the boot out and checked the coil and ran the car for another 20mins or so. The coil was cool. So before i pull the motor i gave it another comp test 3pots at around the 100psi mark. No 2 nothing zero zilch. checked the shimming and there was clearance. so when i strip it no two wants close inspection. The fuel guage was still a little erratic but that will be down to the voltage regulator as suggested by the forum.

Next step i took out no 2 plug (which had been firing by the way) and i put an air line down the plug ole and it would push the piston down (remove cam tops to check in/ex valves closed)  as the engine would turn until the g/box stopped it. air was pissin out from where i don't know could be carb could be exhaust. then i tried it again and the air line blew its self out of the plug ole so it must have stopped leaking to cause that so it could be a broken vale spring or two then the air closed the valves causing the air line to blow out. I have stopped now to think about the days results and i will go back to it tomorrow having given it all some thought.

Just as a foot note when the car is stopped and hot for a short while then start and pull hard there is a lot and i mean a lot of blue smoke i hope the turbo is not leaking oil into the induction system.

Another instalment tomorrow LOL. 

Just been thinking about it and i will put the block breather into a catch tank to see if the oil is crank case oil or turbo. It is highly likely to be crank case as the compression on no2 is non existent some times it is best to walk away and think about these things. it would be handy to have have a leak down tester i will try phil myer (the minder car owner) tomorrow and ask if they have one in the garage. Thats all folks.

Share this post


Link to post
Share on other sites

Do you have acces to a leak down tester? That will tell, I think, where any leaks are.

Also, you seem well below spec for compressions. iIRC they should be around 180 and within 10% of each other. First time I did mine, I panicked as they were all 110 ish, albeit cold, then someone asked did I have the carbs wide open.

Nope, I did not. D'OH!

Good luck with the sparky bits...

Share this post


Link to post
Share on other sites

Do you have acces to a leak down tester? That will tell, I think, where any leaks are.

Also, you seem well below spec for compressions. iIRC they should be around 180 and within 10% of each other. First time I did mine, I panicked as they were all 110 ish, albeit cold, then someone asked did I have the carbs wide open.

Nope, I did not. D'OH!

Good luck with the sparky bits...

I think the turbo c/ratio is a lot lower than the std c/ratio.

Share this post


Link to post
Share on other sites

Low comp turbo is 130psi....not sure of the HC figure.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×