I would first check the timing, may have jumped a link. Then check for vaccuum leaks. Good luck

Answered by poppers1957
2 questions asked

MAke sure you change that oil before it wipes out the lower end of the motor. :shock:

While the engine is running, remove one plug wire at a time and see if the rough running gets worse or stays the same. The ones that stay the same are the misfiring cylinders. Record those and see of the wires go to the same ignition coil. I think there are 3 coils on that. Weak wires and plugs place extra strain on coils and modules and can compromise them. :idea:

I have seen some scenarios where replacing the ignition coils, ignition module and crank shaft sensor located under the module turned out to be the best solution. Having said that, this may not be a ignition problem, but a timing issue as poppers1957 stated. My past experience falls more into ignition, but silver bullets are not fully realized until it runs right :wink:

Answered by Service Writer (expert)
9,955 answers provided

i own a1990 chevy lumina with under 145K on it. it's got the V-6 3.1 FI engine. the other day i hadda beat it bad to get to work on time and ever sence. it's sat because it is running bad and gas is some how mixing with my oil. i replaced my spark plugs and wires. no change. when i accelerate the car doesnt seem to wanna get out of it's own way.. the only way it gains anyspeed is if i jump on the gas pedal really hard then it goes like a bat out of hell. all my spark plugs where almost perfect with the exception of one (front middle) it was black and wet. i'm not sure what to do if anything. please help me ASAP

oh yeah. it also feels like it's misfiring untill i step on the gas hard, it idles fine and maintains speed fine it's just under any kind of acceleration

Answered by Service Writer (expert)
9,955 answers provided