it runs fine till it gets up to around 200 degrees. then it idels a little rough and sputters a little when i accelarate. but i can still rev it up the redline with no problem. what the hell is going on here, other than the fact i own a pontiac? and i also picked up a bad vibe on the highway over 70 mph, no matter what rpm, so i dont think its anything engine related. any input would be great, yeah.

 

anyone have any ideas, i need to get this thing fixed.

 

After all my mods my car kinda does that. Only when it runs really warm. I just think these LT1's dont like to run hot. It doesnt sputter bad when i do it but it hesitates sometimes when its at about 220 or so.

 

running rough at warm temps is a sign of the optispark starting to go out....mine did the same thing. how many miles are on it? also, the vibration you get is common on fbodys because of the unbalanced stock driveshaft. you can get it balanced or get an ls1 or 1le driveshaft.

 

i was afraid if was the opti. how long does it take to replace that thing? the water pump has to come off doesnt it? any special tools required?