I have an 87' iroc z camaro with a fuel injected 5.7 litter. Only mods is a cat back exhaust system. I have an intermittent Ideling problem. It will drive fine for days with no issues or codes. Then the next time I go to drive it, it won't stay running unless I keep my foot on the throttle. I have a ob1 scan tool but seems lately it has a difficult time connecting to the car. Says vehicle not responding. Have to keep trying and plugging in and out till it will accept and scan the computer. Then it shows code 22 tps sensor voltage too low and a code 15 coolent temp sensor to low, but the temp sensor and voltage on the tps are reading accurately within the ranges stated In my repair manual. If I wait a day or so it will start and run fine, or if I disconnect the battery a couple times. This seems to happen weather it's a cold start or has been driven and warmed up. It's random! Once it's running fine and codes cleared it won't throw any codes till it acts up again. Are the sensors starting to go out or is my computer glitching and going out. Should I replace the computer or could it also be a wire connection problem somewhere? Please any ideas. I'm pulling my hair out trying to figure it out.

 

a failing temp sensor can do what you are seeing. are you getting proper readings from it when the problem is present? i had the same issue with a truck and it was showing -40 degrees.