<VV> Non-Corvair-Troubleshooting Help Needed-92 Cutlass

[Craig Nicol]

Chuck said:
I need some troubleshooting help on my 92 Olds Cutlass with 3.1 multiport
fuel injection.?My son went out to start it and it turned over just fine,
but wouldn't fire without pushing down on the gas pedal. We've never had to
give it gas before when we started it. Also, it won't idle now...if you
don't keep your foot on the throttle, the engine dies. We've never had a
problem with it before and my son drove it with no issues earlier today. It
appears that it was a failure of something.
Any ideas? Could it be?a major vacuum leak, the throttle position sensor or
something associated with the injection system. If it was a Corvair, I could
probably troubleshoot it and fix it with no problem...but have limited
experience with the newer (1992?) engines. Any help would be appreciated. 
Thanks, 
Chuck Prosise
67 low mileage Monza coupe (MONZA67)
65 Corvair 140hp Dune buggy (VAIRCRZ)

Craig replies:
The first thing I would look at would be the intake air control (IAC) motor.
This is what controls the idle speed, it's a stepper motor that opens and
closes a valve that controls idle airflow.  It's supposed to close, then set
itself to so many steps open.  It sounds like it got the closed part
alright, but didn't open again. Put an ear near the valve and have someone
switch the key to ON, you should hear it click closed, then click, click,
click open. Could be a bad valve, could be bad signals. More likely the
valve.  The passage can also get clogged if the throttle body is choked-up
by oil, dirt, or carbon.  There is content here for at least one Corvair:
mine!
Craig Nicol