1996 2.3l idle problems

[tmc553]

Truck drives fine, has plenty (well at least normal) power, no missing, good mileage but when I stop at a light the idle drops down and keeps dropping until the engine is loping and eventually stalls. If I keep my foot on the pedal and give it just a little gas, no problems. Do have a P0222 fault code (throttle position sensor low signal) so that may be part of the problem but from what I've read TPS problems tend to show up in other ways. Any ideas, suggestions are most welcome.

 

[cody93]

check the IAC, may be dirty.

 

[killj0y]

That did it for me, try it at a stop with and without a/c. Is there a difference?

 

[tmc553]

thanks

Time to go pull the IAC and see what happens. Hopefully it's this simple.
No AC, so that isn't a factor.
Thanks.

 

[LearjetMinako]

Yep, check the IAC and give it a cleaning. Also check your vacuum hoses, doesn't normally stall an engine, but will make it idle rough.

 

[four100d]

My 95 2.3 had a similar problem/symptom and it ended up being a vacuum leak. The leak was coming from a bad spot in the intake gasket. Spray some starting fluid around the intake and vacuum hoses while the engine is running and if the idle changes, then you have a vacuum leak.

 

[tmc553]

Thanks all. I've changed the IAC, TPS and connector, sprayed it with starting fluid, changed the vacuum hoses, tried propane along the intake manifold to check for leaks and nothing seems to make a difference. Any one know of the possibility/likelihood of an internal vacuum leak?