87 T/A 350. I think I have more than one problem. It happened one night when a girl asked me to give her a ride home. Ofcourse I was exited, but soon embarrassed when my beautiful ride wouldn't even start! I could rev it up, but as soon as I let off the gas it would die. There was absolutely no idle. It only does it sometimes though. And sometimes I have to give it gas to start, even though it's TPI!(BAD) It seems like it usually happens when it's already warmed up, but not always. What's the problem? TPS, IAC motor? I atleast need some ideas guys. Thanks again.

-Brian

 

It could be the IAC or the TPS, but before you go out and spend a bunch of money on parts you might not need, take 15 minutes to test them. You can test the IAC switching the ignition to ON (don't start) and putting the car into field service mode. You do this by jumping the A and B terminals in the ALDL. These are the two terminals next to eachother in the top right hand corner. This will cause the IAC to go to the fully closed position (or open i can't remember). Either way you should be able to hear it, or if you can, remove it from the TB and watch the pintle. The easiest way to see if the TPS is to good is to a)see if the computer has a code 22 and/or b)get a digital multimeter ($15) and test the resistance. The resistance should smoothly and consistently go down as you open up the throttle. Obviously, if they check out with these it doesn't automatically mean they're 100% but it will give you a good idea. Other than, i'd check for a possible vacuum leak, defective EGR, leaky injectors, etc.

 

You may have a leaking injector(s). The leaked fuel makes hot restarts very difficult, and usually a little throttle opening to admit some extra air will get it started. This generally happens after about ten minutes of hot soak, but doesn't affect a cold restart much since the extra fuel has time to evaporate during the cool down period.

The TPS is a possibility, as is the IAC, but a quick DMM test of the TPS can elinimate that, and the IAC can be cleaned easily. If the minumum air position of the throttle is set correctly, the IAC must be doing something.

 

thanks guys, i never thought about the possiblity of leaky injectors. I hope it doesn't come to that though.