i have a 91 camaro 5spd with a mild 350 about 330hp and the car does not start and idle high then drop down like it should i have replaced the IAC and this did not help. when i start the car it will idle at about 1200rpm but after i drive it it will idle at about 2000rpm and never drop back down i am running the stock 305 chip, what could cause this it alomst seems to be working backwards, when the car was origanal it did not have this problem. for now i have it unplugged and i just have the idle set at about 900-1000rpm but i have to keep my foot on the gas when i first start it till its gets warm enoguh to idle

 

That's the problem right there.


You are in need of a custom PROM/chip, bad. To put it simply, the computer thinks your still running a stock 305 TBI instead of that mild 350. Tuning is the key to making power with TBI.

Check out the DIY-PROM board and start reading.

 

Sounds like you have one hella a vacuum leak. What are the IAC counts, fully warmed up and in gear?

 

guess its time for a prominator and a laptop i tryed about 3 mail order chips which all never worked and was told they most likley wouldnt, other then that the car sseems to run great but maybe i will see some more horses with some tuning thanks guys,

 

Q: mild 350 about 330hp

mild?

what type of fueling? what size injectors? what FP?

Q: guess its time for a prominator and a laptop. data logging too!