badxs

i have a 91 rs that had a 305 tbi in it, the motor went bad so i threw in a 350.i figured that the ecm could compensate for the change, but it just dont run right.so i changed the injectors to 350 truck injectors, the esc to a 350 esc, knock sensor to 350, but i still get code 43, and at idle like crap only in closed loop when the thermistat opens. im not sure if this is a ecm issue or a motor issue? what else do i have to change to get it to run right?

92WhiteRS

My only true suggestion is you need to get a custom chip. Also, make sure you have your timing set and no vacuum leaks. If you have all that taken care of your car should run pretty well. But just to let you know, it may take a little while to get the 350 to run perfectly, it took me a long time to tune it right.

JokerRS

Try to be more specific. You say it doesn't run right .What is it doing or not doing. Example, is it backfiring? does it bog? is it at certain rpm's? You have to be alittle more descriptive. You say you threw a 350 in it. Stock? Modified? Pickup truck? LT1 corvette? What is it out of? Camshaft specs would be helpful.

badxs

ok... its a stock remaned 1991 z 28 350. it has tbi throttle body injection,not tpi.. 1000 miles on it.
it idle rough *** heck, and when i rev it up i feel a partial miss, but never a back fire or a bog,and only in closed loop when the stat opens?????????????????

vjo90RS8

iTrader: (1)

are you running the stock chip, if so get a caprice cop car chip, those things came with L98 cams and 350 TBIs so it should work perfectly with your engine (considering you have a L98 block and assuming the stock cam). Go to ebay and search "tbi cop" and the chip should come up, only $30.

badxs

thanks i wasnt sure if the chip would fit,and just to shed more light on the subject, i have replaced every sensor on the motor the only things i didnt change the tps or iac becaure im pretty sure they are good well im posative the tps is good i scoped it,. thanks