Strange misfire problem
Turbo Mini Forums

Need a bit of help as ive pickled my brain:

Did a few runs at the weekend, but stopped early as it started running rough at idle.

At idle its only running on cylinders 3 & 4 , rev it up or drive it and its fine and on all 4 cylinders runs sweet.

Compression is perfect on all cylinders, not breathing etc

Ive tried a differnt coil pack, leads, plugs, and edis unit, all 4 cylinders have a good spark

If anyone has any ideas id be very greatful
Cheers,
Oli

Loose wire to 1/2 on the coil pack?

Just tried wiggling all the wires, but not made any difference. At idle if i take the leads of cylinders 1 and 2, it makes no difference to the rough running. But when you rev it up and you do the same and you take the leads off it noticeably drops a cylinder.
Basically Im fogged!

Only thing i havent tried changing is the crank sensor is this likely to fail at low revs??

Edited by retroracer1380 on 16th Aug, 2010.

checked for a leak on the manifold gasket? give it a blast with carb cleaner and see if it picks up.

I'm going to say do a leak down test,

I predict 1&2 will be down,

my guess is same as joe C
one and 2 down blown head gasket maybe
compression test it with all plugs in except the one you are testing this will give it away.... easy!

keep us posted

Cheers all for the ideas, cant beleive i overlooked the manifold gasket! Cheers Nick, just gave it a spray with clutch and brake and it runs smoother, im guessing where the carb has been hiting the bulkhead it has disturbed the seal.

FEW lol!!

GinoR32 had the exact same problem, he did all you did and it turned out to be an air leak on the inlet manifold due to a broken gasket

Own the day

Lol, at least its a simple fix!