i have an 83 camaro 305 tbi crossfire, it was running great untill it just started feeling sluggish and eventually when i put it in part it kinda ran like it has a cam! it shakes a whole lot especially when in drive and im holding the brakes, it accually did this to me a month ago but one day it was raining and i backed in my driveway and caused the passenger wheel to spin and it make the car kinda bounce quickly then the problem stopped. so what should i do, when i go to rev the car its like moorse code, meaning its not smooth is like "Bumps" it doesn't realy make a bumping noise but thats how it feels. Please help.

When was the last time you changed your fuel filter or checked your vac. lines?

I did a full tune up around 2 months ago. I did the fuel filt and when i got the car last year, i replaced SOME of the vac. lines. Accually last night i had the car running. and it was still doing the same thing and i heard a popping noise coming from the cat which was gutted because of it being completly clogged. So i wondered if theres a gutted cat then whats popping, so i started punching the cat with my fist a little andi it sounded like stuff inside or it may have been the A.I.R pipe hitting something. so i did it more and revved the car. it got a little better, so i drove the car and it seemed the same, then in my driveway i just drove forward and backed up and did it about 5 times revved it some more and the problem seemed to go away, and that was last night. I started the car this morning and everything seemed pretty good, but now the car idles 300 rpm higher than it did before even when i didn't have that popping sound, Now the only time the car idled this high is before i replaced the one vaccume line that was cut by the previous owner, i think to pass inspection, It was one line leading from the fuel canister up front of the car, i had alot of line so i replaced most of the others. What do you think the problem could be?? EGR Valve?? I know the timin is off too, im trying to work that out as well as this problem that pops up every so often, Guess i got a lemon huh?? haha, I appreciate the help tho.

This sounds like an ignition problem. It could be an issue with cross-firing, weak coil, module, bad wires, etc. The lack of fuel will generally make the engine just hesitate, surge, and miss, rather than run erratically.

yeah, well again as it did the last time the problem went away, I honestly think the problem is that the car does not get driven very often, and like i said with the problem with the car running rich its just killing it, I mean, i do take the car out occasionally and i keep up with the changing the fluids regularly and everytime i fill up the tank i use some prestone gas treatment or octane booster, and about a month ago i used seafoam just in the oil and in the intake manifold, i didn't add it to the gas because of the prestone fuel treatment i have it in.