so my car has a high rpm stumble that I cannot seem to track down. The car has new plugs, wires, ignition control module, coil and the opti is 2 years old and o2s that are a year old. so the other day i noticed my coil was arcing (new delco coil) it looked like it was arcing out of the sides of the coil to the metal bracket that holds the coil. so i thought this could be me high rpm stumble so even though its a brand new coil I change it and put a new wire on it. Guess what the new coil is arcing just the same as the old one. If my opti is messed up would this cause the coil to do this? the only other thing I've noticed was there was a time when I hadn't driven the car for 3 days and it had been humid and rainy out and then when i did drive the car it was miss firing bad but after an hour of driving it went away and hasn't come back. What is going on?

 

doubt i can give any advice to ya, but i have been going throught the same crap. but i did notice something. it only happened after the car warmed up.
is it possible for you 2 take the car out tomorrow morning when it is cold and go straight to the nearest safe place and get on it? see if it misses when it is cold, then as it warms up if the missing/stumbling gets worse?
if that is what it does then we have the same symptoms.

GL and if you do figure it out, please post the results

 

i'll let you know maybe i'll change my stupid opti again maybe i'll get the msd opti since i've gone thru 3 gm optis in like 4 years

 

Is the ground strap connected?

 

Another vote to check the grounds to the engine. Check that they're not only tight but they have a clean surface to contact.

 

i know this isnt my thread. but i seen on another thread where it was another guys problem.
so i went and took the ground strap from the coil off and sanded down the body of the car, just to make sure it wasnt the problem. problem still exist.

any other grounds that i/we should look into?

my problem seems heat related as it gets worse the longer i drive it. but the first 2-5 minutes if i go WOT it pulls fine without any problems.
then the second time i go WOT it will miss/surge 3 or 4 times from say 50-90.

 

Check the ground from the battery to the engine block that located down by the starter.