jac113

iTrader: (4)

I have a '92 Camaro with the 305/5 speed. I've been having high idle problems ever since I got the car. There are no vacuum leaks that I've noticed after doing a carb/cleaner spray test. I recently changed the IAC valve. I've put the car on a scanner while idle was high and it read .86 volts at about 1300 rpm. when it drops it's at .67 volts and at 1100 rpm. I can turn off the car and turn it back on and it would usually idle normal, about 800, but then would jump back up to high idle by itself. WIth engine off the tps voltage would change without any throttle movement. WHile on the scanner the tps voltage never dropped below .67 volts. The car runs fine at higher speeds with no hesitation and idle never drops below normal idle. The max voltage at WOT was about 4.5 volts.

what is the base voltage for these tps's. I only have problems at idle so my mechanic thinks that it probably both a bad tps and a vacuum leak within the throttle body itself.

Any ideas anyone....

1989GTATransAm

iTrader: (3)

I think .67 volts is a tad high. On my "fixed" tps it reads .62 volts. When I had the adjustable tps I had it at .60 volts. My wot throttle usually is around 4.3x volts. I would have to dig out my manual to find out what the factory says.

jac113

iTrader: (4)

I got and SES light yesterday and then it went away. I put the scanner on it later on that night and there were a code 22(tps low voltage) and an EGR code. So I watched the tps voltage again while the car was idling high and the low voltage was actually about .63. I graphed the progression and it was smooth which is why I don't have a hesitation during acceleration and max V at WOT is 4.31. I now know that I have several problems because when TPS voltage was at .63, idle rpm was at 1300+. EGR was at 0% and went to 100% as I pressed gas.

This high idle problem needs to be found quickly, the 305 is drinking gas like crazy!!! The car likes to stick at 1500 RPM and would idle normal if I restart the engine....sometimes.

The warm up is fine, usually 1100 rpm. Oh, and last night, the car was in open loop at a temp of 220+ and then switched to close. THe O2 sensor is a new bosch. The fans turn on at 222 and turn off at about 215.

Please someone, any ideas?????

Big Dave

I'm having an idle issue too, only mine concerns stalling and surging at idle. I'll keep an eye on this thread.
FWIW my TPS voltage is .57 at idle, maxes out at 4.18.

D