I wouldn't expect it to be a compression issue, since the engine acts up only after it warms up. Check your air cleaner first to see if your manifold air temp (MAT) sensor is there. Below is a link to where I put an aftermarket air cleaner on my old 1991 TBI. In the last pic, you can see the sensor (probe looking thing). TBI Air Cleaner

 

It does have one, but whether or not its good is another story. It is caulked in. Is there a way to check for that? or just get one and plug and play, see if it gets better?

 

Hmmm, but then again, that one should trip a code too. Does the rough running get progressively worse, or does it go from fine when cold to crappy when hot, with no degree of difference between?

 

I have the same problem with my 92 RS but mine actually dies out if i don't hit the throttle, a buddy of mine said it was the timing but i don't have the timing tool so i gotta take it to a mechanic and get it done.

 

It gets worse as it gets hot. Not like it flips a switch or anything.

I will get the timing checked.

Thanks

 

Just for the fun of it, check to see how tight your intake manifold bolts are.
What you're describing then, could also be a leaking intake gasket, but only act up after the engine heats up to where things can start to warp.

 

Timing is good.

I will check the bolts. Also I did replace the TBI, so that's new, however, thinking back I can't remember if I got new gaskets with it... Should I replace those?

Would that make a difference?

 

New gaskets wouldn't hurt. If part of the old gasket stuck to the old TBI, you could have a leak.

 

Okay, I will try that next. I probably will not be able to get to it until late next week. Out of town for the weekend and then work is pretty busy this coming week.

Thanks so much. Ill let you know if that fixes the problem!