surging idle when in gear and stopped

[zachary A makoff]

I have a 98 k1500 with a 5.7 in it and I am having an issue once the engine has warmed up at bit an when im at a stop light not moving the engine rpms start surging. It only does it in gear, when I put it into park it goes away. Any Ideas.I replaced the distrbutor with a summit racing aluminum one, put an Accel igition coil, acdelco ICM, IAC is a year old as well as the mass airflow and knock sensor. acdelco intake temp sensor.

 

[RookieCly]

Hi there, I just joined and I’m having similar issues with my 92 c1500 with the 5.0, does yours want to jump forward at stop lights? I’ve done some research and heard it could be an intermittent issue with the tps but I have yet to get a new one to find out.

 

[Sabinoerc]

I have a 98 k1500 with a 5.7 in it and I am having an issue once the engine has warmed up at bit a when im at a stop light not moving the engine rpms start surging. It only does it in gear, when I put it into park it goes away. Any Ideas.I replaced the distrbutor with a summit racing aluminum one, put an Accel igition coil, acdelco ICM, IAC is a year old as well as the mass airflow and knock sensor. acdelco intake temp sensor.

I had a surging at idle once which was a result of marginal fuel pressure. The ECM was kicking in a stall save and engine would run up, then it’d turn off and engine would run down. You may want to check fuel pressure to check that possibility off. Marginal fuel pressure can show up in a bunch of strange ways on these. Good luck.