runs like crap!

[89GTA4EVR]

it's an 89 GTA 350 TPI. Last year before i stored the car for winter, it started running rough, so i parked it and thought of fixing it in spring since i did'nt think it was anything serious. This spring, i looked at it and could'nt figure out what was wrong. It's running kinda rough while driving like if i had a blown spark plug wire. When i hit 60 kmh, it shifts in 4th gears, at low rpm, the car shakes. I changed the whole ignition, plugs, wires, ignition coil, pickup coil, eprom, comp, cap, rotor, EGR valve, and still runs the same. At idle it sounds like it spits a little at the exhaust in the back. I'm thinking a vacuum leak at the plenum but the shop checked for leaks and did'nt find any. I did cut out the screens on my MAFS. I was told it might be that.
Any ideas?

[markd79ta]

Are you getting any codes; have you scanned it? Have you checked the fuel pressure? ...fuel pump? The fuel pressure regulator is also suspect on the TPI motors. Three other culprits include the Throttle Position Sensor, the O2 Sensor, and the intake gaskets. The TPS will give you rough idling, and erratic throttle response and roughness. The intake gaskets will leak water in the valleys between the valve cover and intake...this will also mess with idling and drive-ability Finally the O2 sensors tend to go lazy on the old TPI cars. This will cause the vehicle to idle all over creation, and run rough. My '85 Vette didn't give a code for the O2 sensor; I just had to find it

[MAckDaddyKid2003]

it could be the computer. my 89 iroc was running rough with the check engine light on. i brought it to my mechanic and sure enough the computer needed to be replaced. cost me about $300 for a new stock replacement computer. if i were you i would get the computer replaced and get a perfomance chip. good luck getting the problem solved

[tabahr]

So, Kid.... What is with all the cars in your sig? Do you own all those? if so.... sweet collection! Do you have a picture of all of them together?

[MAckDaddyKid2003]

most of these are cars that my father bought and gave to me to store at my house. i bought the iroc as my first car four years ago and did most of the work myself. i also did the lingenfleter conversion with engine sawp on the other camaro at my friends performance shop. the WS6 is my daily driver. the rest are weekend racers and show cars.

sorry i dont have any pics of the cars up on the site yet maybe within a few weeks