elias_799

iTrader: (8)

i got a friend with a 3.5 charger and his car keeps misfiring on the #6 cylinder. it happens randomly. i have already checked the coil pack and the injector and they are both fine. the only thing else that comes to mind is that the valve spring is about to go. this car is cammed and using factory valve springs.

i know this is not ls1 related but any input would be appreciated.

SUCK MY SS

iTrader: (14)

is it a constant misfire?
how did you check the coil and injector?
it is possible that a valve spring has broken...if in question, inspect it.

elias_799

iTrader: (8)

no it is not a constant misfire. it happens randomly

i checked the injector and coil by swapping them to another cylinder.

i really hope it is not a valve spring because it will be allot of work on that motor.

5.3LJimmy

iTrader: (10)

If it is running a cam other than stock and the tune has not been adjusted, then the cam is causing the misfire. The PCM thinks that the cam is a misfire due to the change in valve events.

elias_799

iTrader: (8)

the car has been tuned. and if it was not the pcm would throw a misfire code for all 6 cylinders then just one no ?

5.3LJimmy

iTrader: (10)

Not necessarily. I put a cam in my brothers 4.3L S10 and it was only showing misfires on cylinder 4. I would talk to the person that tuned it to see what he has to say before doing a whole lot of work for what may be nothing.