I know this is not camaro related but it is TBI related.

87 Suberban 3/4 ton
It idles good in park or neutral, but when you put in drive or reverse it stalls out. The IAC seems a little slow when the scan tools is hooked up. all the sensors have been replaced including the iac. the prom and computer have been changed. fuel pressure is at 13psi. IAC passages cleaned out. The timing has been double checked.

If anyone has any ideas it would be appretiated

Thanks
-Walter

 

Did you try resetting the base Idle? Too do this you must

1} know how to get you car in field service mode
(short pins A and B) In the ALDL this will seat the IAC in 45 secs.
2} After 45 Secs unplug the Iac and the Timing spoct connector
3} Start enigine and note Idle RPM's (my guess right here is that you wont even start at all)
4} adjust you throttle stop screw till you get 550 RPMs ( you may need to turn this up till you can get the car to Idle) then turn done as necceary
5} turn car off then replug everything back in.
6} depress gas slightly then start car and leave it high Idle for 5 secs
7} Shut car off then let sit for min 10 secs
8} restart car and let ldle return to its normal setting.
The car may not come down to it previous Idle but after a few trips it will relearn as nessary