missfire

[Darren.]

I have a missfire on cylinder 2. The compression is good.The cylinder head is a reconditioned on by Minisport.
There is a spark to cylinder 2.Tested by lifting the lead and looking for a spark.
I have swapped leads round and plugs round to eliminate either of those.
Bought some new points/condense/red rotor arm and new cap.
The problem is still there.
Any ideas ?

[simmitc]

Try viewing it running in the dark with no lights. If there is any stray spark then it should show up. From what you say, I'm not expecting you to find anything, but it might be worth checking, if only to completely eliminate the HT side.

[bufferzone]

From 7 years ago. Simmitc, do you remember this? It was a clogged air filter causing the misfire

viewtopic.php?f=4&t=49906

[oliver90owner]

Valve sticking open? Cam lobe worn? Bent pushrod? All things to check if it is not electrical. Even a leaking inlet manifold gasket can affect one pot more than another. Myself and my brother have suffered all of the above faults in the long distant past.

Likely more info needed - is this engine standard or ‘breathed on’?

[simmitc]

From 7 years ago. Simmitc, do you remember this? It was a clogged air filter causing the misfire

Couldn't forget it , but the current topic was very specific about it being No 2 whereas mine was not attributable to any specific cylinder. Still, that thread will provide just about all the advice one could ever want on a misfire

[Darren.]

Thanks for all the replys chaps.I think i might take the head off and investigate further

[Darren.]

P.S the engine is standard as is the air filter

[pgp001]

Can I just ask why you say it is cylinder 2 please.
Is it because you are you getting no change in running when you pull the plug cap ?

Phil

[oliver90owner]

More info? What were the compressions when you tested it? But, go ahead snd remove the head if you must - but I fail to understand exactly what you expect to find (that you can not diagnose with the head on).

[Darren.]

Can I just ask why you say it is cylinder 2 please.
Is it because you are you getting no change in running when you pull the plug cap ?

Phil

That is correct Phil.No chage in running after pulling the plug lead

[Darren.]

More info? What were the compressions when you tested it? But, go ahead snd remove the head if you must - but I fail to understand exactly what you expect to find (that you can not diagnose with the head on).

Off the top of my head I can not remember the compression readings as it was many moons ago (House move wife move etc etc) I do know at the time the compression was good and similar at all four cylinders I suppose I could check it again when I get my tackle back LOL. My gear is spread over three garages at the moment.Im wondering if it may be a case of me in the first place messing the assembly up of the head refit. The car will drive in a fashion but I know something is a miss.

[oliver90owner]

Off the top of my head I can not remember the compression readings as it was many moons ago (House move wife move etc etc) I do know at the time the compression was good and similar at all four cylinders I

Was it mis-firing ‘many moons ago’?

[simmitc]

This does seem like additional and material information. I suggest starting from scratch. Forget everything so far discussed. Push the car out of the garage or wherever it happens to be stored. Perform a compression test and record and report the readings (dry and wet cylinders). Start the engine. How is it running? Remove each plug lead (one at a time) and record whether there is any difference in engine behaviour and report all results. Do not, at this stage, swap any components, just record and report. We will then have an accurate picture of what is happening at the moment rather than some months ago; and can offer some relevant suggestions as to how to proceed.