Now What!!!??? ****** mis-fire

[jcb]

pulled out of a junction rather exuberantly and about 20 yds down the road engine died!
started up with misfire on 2 cylinders (not this again I thought, thinking of the broken MAF situation i had that cost me 6 hrs on tha A1!)

pulled away and as revs rose 4 cyl kicked in.
doesnt like high load/rev combos and drops a cylinder

need to VAG it today but not looking forward that!

 

[Bradderz_1988]

Try popping the connectors of the coils 1 by 1 see if drops a cylinder or stays the same.

 

[Broken Byzan]

ICM would be a guess, only thing that is connected to more than one cylinder assuming mechanicals check out

 

[jcb]

ICM?

 

[aragorn]

ignition control module.

Its on top of the air box.

 

[jcb]

yes I see, googled it.

only done an engine code search and it was clear
am about to do a full search when I can find the laptop charge cable

 

[Broken Byzan]

It rarely throws a code on the std engine management sadly.

 

[Bradderz_1988]

Mine didnt when it dropped a coil just popped and swapped to find the ****** lol

 

[jcb]

useless system that can stall the engine and run on half the engine and the ECU thinks its normal!

 

[Foxmeister]

useless system that can stall the engine and run on half the engine and the ECU thinks its normal!

Slightly off topic, but why did you choose your username JCB? Keen interest or operator as a job???

 

[jcb]

ha, its a long story!
I needed a psuedonym for a job I had 15 years ago (think of "James" in the Bangladesh call centre but different!) so I stole the name of a guy I went to school with, initials JC.
Didnt want to look like I was the second coming of Jesus so I put the B after it!

 

[Foxmeister]

Ah right, good idea!

Thought there was an up and coming yellow respray maybe with the addition of custom rear stabilisers for the Audi! lol

Would love a shot of a 3CX thou!

 

[jcb]

so it is dropping a cylinder under load or highish revs
few hundred yards later of driving like miss daisy and it comes back on all four.

if I can get it up to speed with medium revs and under light load it will come back on all four cyls


is there a block I can monitor or log with VAGCom to see what the ignition is doing before I start replacing ignition components willy nilly?

does this sound like an ICM?
do I buy new? (again)!

 

[aragorn]

Doesnt really sound like an ICM, they usually just die and the cylinder simply never fires.

I presume you've checked all the spark plugs first off?

If so then get yourself a known good coil and swap them out one by one until you find the culprit.

If swapping coils round doesnt fix it, then try another ICM.

 

[jcb]

plugs are brand new, coils were checked when the MAF died 2 months ago, could check them again I suppose but the problem is it only ever misfires when giving it large at high revs or high load

soon as you pull over it stops!

anyone got an ICM they want to load (possibly sell!) to test that theory?

 

[aragorn]

Brand new since the issue started? Or just changed recently?

I think i have a spare ICM, will have a look in the garage.

 

[jcb]

8 weeks.
have a new set that I may try
could really do without shelling out for new coil packs and ICM's

will swap plugs out and check some coil packs to see if I can pin it down

cheers

 

[aragorn]

Even if you just take the plugs out and check them, rules out the possibility that ones fallen apart or something!

 

[murran]

wonder if this is oil pressure related?
as in the relief valve is stuck shut? so when you boot it up to high revs the oil pressure is passing the 70 odd psi the relief valve should limit it too.
the high pressure jacking the lifters up causing the valves to not be able to shut completely?

does it do it worse/more from cold/warm than it does when hot?

 

[jcb]

cant say I have noticed a link.
would say that most times it has happened the car has been running more than 5 mins, but short journeys so may not be fully up to temp in this inclement weather.

will pull plugs and mess around with coils

cheers