2000 Saturn SC1 High engine idle

7SSTREETSTOCK

MEMBER
2000 SATURN SC1
4 CYL
2WD
AUTOMATIC
188,000 MILES

I have been working on a saturn sc-1 for a friend of mine. He has had transmission issues in the past, and a few minor engine related problems. The primary problem we are fighting now is the engine will not idle below 1400 RPM. I have a code reader which is giving me a code for IAC engine RPM too high, and Bank 1 too rich.

I have replaced the IAC valve and cleaned the throttle body. I have even replaced the throttle position sensor and one of the o2 sensors. Yet I still have a high idle. I have hunted for vacuum leaks, and even checked the egr system for proper operation.

Someone please help me. This is my friends only ride and I need to get it running right ASAP!

Thanks

1 Reply

SATURNTECH9

MECHANIC
30,869 POSTS

What are the code numbers u have in the computer?I would check the little s shaped hose that runs from the valve cover to the intake manifold they get holes in them and colasp. Also I would check at the intake manifold gasket where the intake meets the head around the number 1 and 2 cyl which is if u go to the passenger side the first two cyl from left to right most of the time u can see the gasket wrinkled. If u let the car idle and spray carb around every where if the idle goes up or the engine stumbles or dies then u have a leak there. Also u can check the coolant temp sensor it's screwed into the head below where the upper radiator hose goes onto the head. It has two wires going to it a yellow wire and a black wire. The sensors crack and leak coolant into the connector see if the connector is corroded if it is u will have to clean or replace the connector. Make sure the car is cold when u check the sensor u will loose coolant. The sensor is under 20 if u replace the sensor make sure u get a brass tip one the plastic tip ones crack. See if urs is cracked a bad sensor will cause all kinds of problems high idle stalling no starts surging over heating etc. Let me know what u find.