94 1.8 misfire/judder when idle - mad_revs1
hi new to forum recently bought a old cav as a winter hack while motorbike comes off the road for the winter.was running perfect when i bought it.parkesd it on the drive about a week later replaced rocker cover gasket as it was leaking,topped oil up with some 15w40 semi synthetic.started it up and now there is a horrible vibration when inside the car and the engine is slightly misfiring.removed plugs to find out which cylinder was misfiring seems to be no.4 as plug is a soot black colour where the other 3 are tan.replaced all plugs and leads but still with no joy.is it just co incedence that this occured when i changed rocker cover gasket.also cyl no.4 lifter is tappy which it wasnt before i changed gasket.the old gasket was a cork one and had to be scraped off,if a bit of old gasket flung intothe top of the engine.could this cause the misfire.or is it a sticky lifter as it had sat for 2 weeks before i bought it.i have put some hydralic lifter treatment in incase it is a sticky lifter but cant drive it as am not insured yet so can only rev it on the drive to work the treatment round.
any help suiggestions greatly appreciated as unsure what it could be
it is a 94 lreg cavalier 1.8 auto fitted with c18nz engine and it has the ignotion where there is no dizzy cap.thanks
94 1.8 misfire/judder when idle - mad_revs1
car uses no oil and as soon as you raise the idle with accelerator missfire and vibration goes.
94 1.8 misfire/judder when idle - Victorbox
A good place to ask is these two sites.

www.vauxhallownersnetwork.co.uk/forumdisplay.php?f...2

www.vodc.co.uk/index.php