Hi all i have a 91 vzn130 3vze v6
it is idling at 1500rpm i have replaced the throttle body checked the maf sensor all readings within spec
cant find any air leaks
it is running smooth
seems to have normal power at highway speeds and around town
the efi coolant temp sensor is below spec it should read between 2-5k ohms when tested and was reading about 90,

will the efi coolant sensor cause the engine to idle at 1500rpm or should i be looking at ecm as well

 

If the cold start injector sensor is stuffed that would more than likely cause a high idle. Ive recently bough one one ebay for $8 to replace mine because it was old, brittle and i managed to snap it clean in half with a gentle tap from my knuckle. Im guessing because ur testing sensors that uve tried and cant get it to idle nicely just by adjusting the idle screw on the throttle body?

 

the idle screw is all the way in and still idling at 1500 i slackened off the throttle cable to eliminate that the cold start injector timing switch is ok the problem i think is the EFI coolant temp sensor i did the same thing and snaped the top of cold start injector switch it didnt affect idle just made it a bitch to start when cold

 

have now also replaced cold start injector time switch and engine coolant temp sensor have checked valve timing and ignition timing could a dodgy o2 sensor in the exhaust cause it to idle at 1500rpm next step will be to start chasing wiring at the ecm to try and determine which if any circuit is faulty and re check for airleaks could a faulty pcv valve cause it i am running out of ideas

 

It is possible the shaft on the throttle body is worn allowing more air into the engine.

The butterfly valve might have moved off center as well allowing more air in