i have replaced a parts cannons almost every sensor in this 87 GT , vac lines, egr and sensors,tps, distrib w/ icm trying to stop the high idle(1200), does idle down to a 1000 after warm up. new ecu, had to change mat sensor in air filter area due to mice eating wire. would a bad air charge temp sensor cause a high idle ? during warm up? have not changed cold start injector o rings yet, could this cause my higher idle? at wits end on this thing !
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
i replaced MAT, in air filter can, dont think i have replaced air temp module below thermostat housing. would this cause higher idle ? it idles arond 1200. when i put in gear it will try to idle down to under 1000 stumble and die sometimes not all the time ?.restart it and idles back up to 1200. then put in gear again and it stays 1200. its like its trying to come back to correct rpms but something is telling it to idle back higher ?
"mice"implies plural, more than (1). Are you sure (they) didn't have a smorgasbord on the entire harness in areas you can't easily see? This happened to my 2011 CTS and the number of codes (over 7) that showed up was breathtaking. $1800 worth of damage, but it still ran in limp-home mode.
Check your harness's closely.
Spoon
------------------ "Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut
[This message has been edited by Spoon (edited 11-13-2023).]
You need to get a scanner on there to see what temperature readings from the MAT and CTS are being sent to the ECU. Incorrect readings can affect idle RPM, as will vacuum leaks.
You need to get a scanner on there to see what temperature readings from the MAT and CTS are being sent to the ECU. Incorrect readings can affect idle RPM, as will vacuum leaks.
Before changing anything, check resistance with multimeter of MAT and CTS. At ambient temperature, they should both read the same.
At ambient temperature, they should both read the same.
When I've checked mine, I've done it in the morning after the car has sat all night. The readings are usually very close to each other. If not, then there's a problem!
