3.4 MISS/SKIP

[sharkbyte427]

Hi,I have a 1994 GTP with a 3.4 and have replaced wires and plugs and have checked for vacumn leaks can't find any.The car has a dead skip on #6 cylinder.It is firing fine on #3 sister cylinder so I could use some input.Any suggestions out there.Any help is still help.THANKS,JERRY

[pepsi_coke]

How many miles on car?

[sharkbyte427]

HI,Just rolled 105,000

[sharkbyte427]

I also forgot to mention that sometimes it's hard to start.Stepping(not pumping)on the gas seems to help.Also when I hook up my inductive timing light to #6 wire it seems like it's firing twice as fast as any other plug wire I hook to.At first I thought it was the only one firing right but when I disconnect the wires one at a time,It is the only one that dose'nt seem to make a difference.Please,help,help,help!!!I know this car is capable of much better performance.I hear stories of these things beating 5.0 mustangs from stoplights!THANKS,JERRY

[pepsi_coke]

LOL, I dont know where you heard about 5.0s .. but if I was you, I would recheck that plug, replace the ICM and correspondin DIS coil.

-Jay

[sharkbyte427]

Hi Jay,I saw the 5.0 comment On another grand prix forumI just replaced the plug with another ac double platinum,the first one looked fine but when in doubt,I replaced it anyway.Im curious,If the coil were bad-would'nt it affect the corresponding cylinder?#3 seems to be firing just fine.THANKS,JERRY

[pepsi_coke]

Yes, the DIS system has 3 "coils" .. each coil controls 2 cylinders.

[SappySE107]

Have you checked the fuel injector or the fuel pressure regulator or the fuel filter? Could be a fueling problem on cylinder 6.

I wouldn't run platinum plugs. Regular AC delco do the job and are less expensive.

[sharkbyte427]

Hi,Yes I checked the fuel pressure,The injector harness and the actual injector.Everthing is within specs.What baffles me is the fact that the #6 cylinder is not getting the same amount of fire through the wire as #3 which is on the same coil.I'm assuming this based on my inductive timing light which seems to fire twice as often on #6 as any other cylinder.

[Synestral]

Have you checked for a spark leak? If there's even a tiny hole in the insulation, the spark will usually jump out to whatever is a good ground.

[sharkbyte427]

Hi Folks,Thanks for the help but mystery solved.I only have about 40 pounds of compression on #6 so I'm guessing bent/burnt or stuck valve.She does'nt burn any oil so that should rule out rings.Does any body know a ballpark labor price on pulling the front cylinder head and replacing the head gasket.I can get the machine work done myself.THANKS,AGAIN,JERRY