Hi, I have a 95 saturn sl-2 that has been having idle problems and stalling. The idle will rise to 2000 rpms or so when I start it then slowly come down to between 1000 and 1300. And sometimes the idle will be high and then out of nowhere the idle will drop to the normal 6-700 rpms. It also stalls occasionally. I have changed the iac, the tps, I cleaned the throttle body and the intake, I put a new map sensor on and still wont fix it. I brought the car to some guys house and he scanned it and the maps code came up but when I put it on it didn't do anything. Maybe he just had a cheap scanner. Do I need a new pcm? Or what could be the problem. Please help me, I dont know what else to do and the car is using more gas than necessary because of the high idle.
Just to add to this one has anyone checked the coolant temp sensor the bottom one with two wires going to it?Its very common for them to fail and will cause high idles stall no starts all kinds of issues. Also inspect the inside of the connector if the terminals are green or blue instead of silver you will have to replace the connector also. Its real common for the sensors to crack and leak coolant into the connector. Alot of people over look a bad coolant temp sensor on those cars.
May, 3, 2012 AT 11:51 PM
How does that affect the idol? Im open to anything but that doesnt make sense.
May, 4, 2012 AT 12:12 AM
If the coolant temp sensor reads colder then actual temp the computer will raise the idol.I have replaced hundreds of these sensors for high idols surging while driving no starts overheating all kinds of symptoms. Iam a factory trained saturn tech worked for saturn for over 16yrs so I know these cars inside and out. Have done everything on your car bumper to bumper. Thats why the coolant temp sensor is usually over looked.A lot of people dont relize how that temp sensor can affect the way the engine runs. It tells the computer the engine temp if the computer gets the incorrect temp it can under or over fuel the engine.
May, 4, 2012 AT 12:18 AM
I have even seen a bad coolant temp sensor cause the idle to surge up and and down over and over again.I have seen them when they go bad have a 30-40 degree flux change up and down while the car is running.I saw one that was over a hundered degrees off temp wise. It may not make sense to you but makes sense to me I have seen them do some oretty crazy things that even suprized me it was a bad coolant temp sensor.
May, 4, 2012 AT 12:34 AM
Im not trying to second guess you. Ill give that a try and let u know what happens. Thanks for the advice, I appreciate it.
May, 4, 2012 AT 12:50 AM
Make sure its the bottom one with the yellow wire and black wire going to it. Also inspect the inside of the connector if the terminals arent silver replace the connector also.
May, 4, 2012 AT 7:48 PM
I replaced the temp sensor and checked the wires and its ok. So now what should I do. I was really hoping thats the problem. Any suggestions?
May, 4, 2012 AT 8:33 PM
So you replaced the bottom sensor with two wires going to it?It still does the same thing with the new sensor?Also is the check engine light on any codes?You mentioned a map code I didnt pick up on earlier?What is the exact code number you have?You can flash the codes out without a scan tool on that car.