misfire

jidasas · Post by **jidasas** » Mon Nov 10, 2008 3:47 am

any suggestions for why my car would be missing and misfiring so bad that it dies? it only does it on cold mornings and if I let it warm up for about 10 minutes it doesn't do it...it also backfired the other day and for some reason when it did it had enough pressure under the cam cover to pop the gasket out...it also pushed oil out from under the oil cap and popped the dipstick out? I've checked everything as far as sensors go..i.e. iac, tps, cps...etc. I also checked the spark plugs...they are all light brown...which means that the spark is good and they are not fouled so what else should i check? any recommendations? need to get this sorted so I can start my turbo work on it since I have another car to drive now.

Jimmy

MMamdouh · Post by **MMamdouh** » Mon Nov 10, 2008 9:00 am

extra pressure in the crank case points to a bad piston ring assuming your PCV is not blocked... combustion chamber pressure is being transferred to the crank case through the worn rings

MMamdouh

daewoomofo · Post by **daewoomofo** » Mon Nov 10, 2008 10:39 am

could it be a blocked cat?

MMamdouh · Post by **MMamdouh** » Mon Nov 10, 2008 12:01 pm

ummm... how would a chocked exhaust piping discharge in the crank case?

MMamdouh

jidasas · Post by **jidasas** » Mon Nov 10, 2008 12:37 pm

I don't think i have a bad ring/rings...it never smokes at all if it does turn out to be rings it's ok since I've got new pistons to put in anyway. I'll check the pcv tonight. thanks

Jimmy

Big Jeff · Post by **Big Jeff** » Mon Nov 10, 2008 3:32 pm

when it does drive, does it feel like it has a lack of power

daewoomofo · Post by **daewoomofo** » Mon Nov 10, 2008 9:51 pm

MMamdouh wrote:ummm... how would a chocked exhaust piping discharge in the crank case?

MMamdouh

my thought was that if there was a build up of pressure from a blocked cat it would need to go some where, and it might have chosen to go through the rings, if they are a bit worn, but im prolly wrong so ill shut my mouth now

jidasas · Post by **jidasas** » Mon Nov 10, 2008 11:58 pm

it doesn't feel like it has any less power when the engine is warm...when it's cold it feels like it's running on two cylinders or something.

Jimmy

mezomaster · Post by **mezomaster** » Sun Jan 04, 2009 4:05 pm

my conclusion it may be a weak crank angle sensor which works well when it warms up and this causes a wrong firing order which made the compression moves to the block through the rings, this also maybe the module it self, i faced a problem somehow like that before with a module which was making the car goes 3 cylinders untill it warms up then it goes 4 cylinders, piston 1 and 2 was getting the right spark in the right time but the spark was changing from piston 3 to piston 4 in the wrong firing order untill it warms up then everything is ok