89 camaro 305TBI stalls??

[blkchevyrs]

I have a 89 Camaro RS with a 305TBI. It stalls out when it is in reverse or when at a low idle. It is a remanufactured motor and has many new parts. I replaced the EGR valve, IAC valve, TPS, air temp sensor, new ignition (was sending out bad codes and causing car to stall), no vaccum hose leaks, new fuel filter, all new plugs and wires, but the car continues to stall out when in reverse or at a low idle. However, it does not stall out all of the time because sometimes it just hesitates. But if I run the AC the car will not stall out at all and it will does not hesitate. It also has a fuel smell which is very potent. I am really confused because prior to installing the new engine the car did not have a problem stalling out. If anyone could help I would really appreciate it. Thank you!

[Tech II]

What are the RPM's at dile? Should be around 600rpms....minimum idle may be set too low....with A/C on, the ECM raises the rpms.....could have a bad/lazy/crudded IAC pintle, or the throttle plate and bore could be crudded up....

[blkchevyrs]

I am not sure the exact dile of the rpm's because the gauges only work part of the time. I just know the mechanic told me that when its at normal or low rpm it tends to stall out. I've been having this problem for about 8 months and no one can figure it out. I will also check what you told me too. I was thinking the throttle body itself may be bad. I also replaced the computer so i know thats not bad and the fuel injectors are good i've had them looked at. How would i go about checking the pintle and other things you said could be crudded up? Or could you link me to a website that explains it? thank you again

[Tech II]

Basically, look at the throttle plate when it is closed.....manually open it and look where it makes contact with the bore of the throttle body......you will probably see black crud where the throttle plate mates the bore....also crud around the outer edge of the throttle plate......spray carb cleaner into a rag, and wipe the edge of of the throttle plate clean and with the plate held wide open, wipe off the crud on the edge of the bore......

Remove the IAC valve......clean the crud off the pintle of the IAC valve.....also clean the bore the pintle mates with with a wet rag of carb cleaner....OR, I just dip a Q tip in carb cleaner and use that to clean it...then wipe clean...

Another problem happens if, you disconnect the battery, for any reason......when you do this, the computer has to relearn the position of the IAC......this is called idle learn procedure....

AFTER CLEANING THROTTLE PLATE AND BORE, and then the PINTLE AND BORE, with key out of the ignition, disconnect the negative cable....wait a few minutes and then reconnect.....

Block rear wheels.....apply e-brake if it works.....start vehicle, apply brake pedal and shift car into drive......let vehicle idle for 10 minutes.......shift to park, shut off vehicle....wait 5 seconds.....start vehicle and do same procedure for another 5 minutes......then shift to park, and shut off.....IAC position should now be learned....

See if this helps the stalling problem....

[Genopsyde]

$20 says it's a faulty CTS (coolant temperature sensor)....the one for the ecm, not the one for the gauge.