i have an 89 s10 with 4.3L fuel injected. when engine get warm, the truck idles down and dies when stopped. when moving truck runs fine. is there a possibility it is the TPS? the truck used to idle high before and then stopped idling high about a month before this issue.
There are two things that could cause this, one is the IAC (idle air control) motor is clogged with carbon and can't respond properly to the commands from the ECM (engine control module). The other is the throttle body base gasket may be bad and needs to be replaced.
When the throttle body is removed you can service both of these items. Cleaning the throttle plate should also be done while the throttle body is off the engine.
This should get your engine back to normal.
If you can let us know if this information helps you, if not we can diagnosis the problem further.