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jhue's Garage

2009 Pontiac G8 GT 4dr Sedan

Questions & Answers

Mechanic Q: misfire or dead skip?

It has always had a slight stutter when you go WOT but not this seeming dead skip. Have not put it on to an occiloscope to see if I can determine if it is always the same cylinder yet.Before this started it would run great with only the slight stutter @ WOT.

Mechanic Q: Replaced opti spark ,coil, plug wires,and plugs now car has a real stutter and you cannot drive it i?

Car has almost two hunderd thousand miles all highway typical LT-1 oil leaks. However after replacing all of the Ignition typical parts including Opti -Spark plugs wires coil and the Opti harness the car will not run with any power and at idle you can hear a cylinder missing but it does not do it all of the time. this is my first experence with the LT-1 . I am now wondering if I have a broken rocker arm any thoughts would be appreciated . also it is showing no codes

A: Replaced opti spark ,coil, plug wires,and plugs now car has a real stutter and you cannot drive it i?

haven't ran a compression test as of yet and before it had just a slight stutter @ WOT but did not skip. I have not put it on to an Oscilloscope yet to determine if it is the same cylinder each time. I cannot find any timing marks on the balancer or on the Opti Spark. Should the # 1 cylinder be at TDC when installing the OPTI Spark? I have heard that it should be either on #1 or #6 TDC which is correct if it has to be at TDC to install.

Q: Replaced opti spark ,coil.plug wires,plugs car acts like it has a dead cylinder and no power?

Have tried almost everything to find problem it appears that one cylinder is missing under a load ,in neutral runs fine with an intermiten skip.