my new (to me) lt1 runns great, but after it gets to full operating tempature and then about ten minuites later it starts to miss, then after a while its makes the idle fluctuate and the whole car shake very badly. it does the every time and you can almost set your watch by it??? it dont think its tempature related and the only thing i don't have hooked up properly is the vacume line on the tranny, when i got my engine&trans it was cut and i don't know where it goes??? my book doesn't show any vacume line to the trans!!!

Also does the impallla ss have a speed governer because at about 70mph with my 3.65 gears (computer thinks its going probably 90-100) the car dies until i drop down in speed a little and then kicks back in???

Thanks,
Maurice

 

i have the same problem but all my lines are hooked up properly and im just plain lost on what it could be. ill try the mafs because i have an extra and ill let you know if that is what it is . also when your driving or about to take off does it respond properly if you mash the gas?

 

I sounds ignition related possibly the coil or module heating up. And if you have a civilian caprice tune in your computer it has a 108 speed limiter on it! the 9c1 and impalas got higher ones. What kind of car and where did you get the gear ratio numbers??

EDIT: On the vac line issue there is no vac line stock.Someon put a vac modulator instead of a force motor in there or your getting something mixed up..

 

oxygen sensors.... say it with me.... CLOSED LOOP PROBLEMS