Citroen C2 1.1 Idle Misfire


http://www.bba-reman.com/forums/Topic174092.aspx
Print Topic | Close Window

By Dibber - Tuesday, February 05, 2019 5:34:39 PM
Hoping someone can assist me in finding the cause of a misfire on a recently purchased C2 1.1..

The background is I purchased the car from a friend who was a Psa technician for 35 plus years. He got the car from the dealership he used to work in prior to retiring. The car had a broken timing belt. He replaced 4 exhaust valves.

From the day I got it from him it's had a misfire at idle. Seems to run fine beyond idle. It sounds like it drops a cylinder every now and again. Approximately ten second intervals. At exhaust you can hear it splutter every so often.

So far this is what I have done. Compression check. 210 psi on all but one which was 205. Valve clearances checked prior to compression check.
New spark plugs fitted (NGK).Throttle body and MAP sensor cleaned. EVAP solenoid checked and appears fine. Crank sensor resistance measured and spot on.

Fuel trims are showing slightly lean condition at 2.35 %

I thought I had found issue as there was a leaking injector seal. Seals were replaced and injectors cleaned. Injector resistances checked and all were 12.4 ohms. Fuel trims have lowered slightly to 2.25%.

A further vacuum leak check with spraying water around manifold shows no further leaks.

I don't have any fault codes showing. Anyone got any ideas where to look next?
By Robski - Tuesday, February 05, 2019 5:56:41 PM
It sounds like it drops a cylinder every now and again.

Anyone got any ideas where to look next?

yes, pinpoint which cylinder/s & work from there.
By miketribe - Wednesday, February 06, 2019 2:16:29 AM
A further vacuum leak check with spraying water around manifold shows no further leaks.



Try a smoke test.

Mike
By Dibber - Thursday, February 07, 2019 11:58:40 AM
Thanks Mike & Rob for your replies.

Quick update. Today I checked the fuel pressure and it's spot on. I took Mike's advice and tried a smoke test. Thought I may have had a very small leak on inlet manifold to head area so removed manifold and fitted new seals.

Bottom line.. it's exactly the same and diagnostic figures remain unchanged.

When finishing up work on it today I did discover one very unusual thing. If an electrical load is placed on engine the idle becomes a lot smoother. It only needs the side lights on to achieve this. I would go as far to say it idles the way I expect it should.

I don't quite know what to make of that.. Have I some sort of electrical issue? I cleaned all the engine side earthing points the other week..
By Tismot - Thursday, February 07, 2019 2:37:29 PM
Question; is it worse when warm?
By Dibber - Thursday, February 07, 2019 5:45:16 PM
It does get more pronounced the warmer it gets..