After I drive my truck and park it for any period of time and then restart the truck it will sputter and backfire rpms do not go over 1500-2000. If I put it in neutral and rev the engine this will help but not always correct the issue. Eventually if I just push through it after 2 or 3 min it will go back to normal. I replaced the spark plugs, wiring and distributor cap. I have also changed the O2 sensors nothing seems to help though.
You might want to try cleaning or replacing the idle air control valve (IACV).
If cleaning the IACV does not help…try replacing the TPS (throttle control sensor). I owned a 2002 model and that turned out to be the problem with mine. Once the engine heated up…the TPS would go wonky after it was shutdown and then restarted.
Backfiring occurs b/c gasoline makes it way to the exhaust pipe. Which means the mixture is on the rich side. The O2 sensor/ECM feedback loop is supposed to prevent that, but unfortunately the O2 sensor doesn’t work until the engine is warmed up. If the above ideas don’t help, might be a good idea to get a fuel pressure test. You may have an injector leaking into the intake manifold a little.
Thanks so much Guys ill look into this with the holidays not sure how soon. When I do ill let you know what worked or didn’t. I really appreciate the advice.
I replaced both the IACV and the TPS its not doing it as much and runs smoother in general but it is still happening, any other suggestions? I thinking maybe the Computer.
I think George is on the right track with the idea of a leaking injector.