Ok so i have a 1990 firebird with a 3.1L v6 i started having problems with the idle when i would come to a stop it would want to die and half the time it would die, usually restarted right back up, it also has a slight miss fire you can hear in exhaust. so i replaced the TPS, Plugs ( NGK ) wires, Ac DELCO Distrub cap and the rotor in cap, and used almost half bottle of carb cleaner on the EGR and still same problem, also looked all over for vaccume leak. so i replaed the IAC now in the morning it idles at 2300 rpms and after i drive for a little it will drop to around 1500 ( in drive) then eventually it will have the same problem with dying when i come to a stop. So i did a idle re-learn and it ran good for 2 days ut still had slight miss fire, now im back to it idliling very high and after around 20 mins of driving it will want to die...Im Clueless from this point. Also there is no check engine light on. What do i do?

 

I also have replaced the transimmision in march but i had the idle problems befor but they went away for a while and now are back

 

Check the injectors. Check for gas in the fuel pressure regulator vacuum hose. Then take it from there.

 

Find the miss fire, and repair first. Buy a foot of windshied vaccum hose about 7/32 or the size that would fit between distributor cap and plug wires. Make the length about 1 1/4 inch long. Washer hose has graphite and will run the spark thru them. Now start the car, use a test light or ground wire and touch the rubber hose (ground the spark so it will not get to the spark plug) one at a time. Listen to which one doesn't drop the rpm down. Thats the miss firing cylinder, can be more than one. If you pull the plug out, check the cylinder compression also.

 

well i took it to a mechanic and he told me the diagnostic sad the computer is fried that the prom in the computer is fighting the EME i belive is what he said but he said you cant buy this part anymore and that each part of the computer has to be coded with the car....so idk what to do....

 

Do have manual (Chilton) for the car? If no get one and read up on the engine management components and learn how to check them. Have you check the egr for being stuck open? Have you tried blocking it off? Have you check the injector resistance? Have you tried jumping the terminals on aldl output to read codes? There are a bunch of things to check before believing the computer is fried.