IAC issues

[NewToDSMCars]

I have been hunting all over for help with an issue I am having with my 97 Eclipse. It revs up to 4500RPMs on its own and tests on the IAC show its not moving so I went to the parts store and got a replacement put it in no change I took it out of the throttle body and had a buddy turn the key forward and the new one does not move just like the old one, So I returned it and got another new one just in case and still the same thing the IAC will not move and just instantly throws a Idle Control System Failure code as soon as I start it even after clearing the codes. Could this be my ECU? I notice the wire harness for the sensor is melted I am wondering if it shorted out something in the ECU before the last person who had it taped it all up. I have pulled the whole harness out off all the sensors and fixed any spots I found to be bad in hopes that it may just be the ECU but I do not want to spend the $200 if I don't have too.

 

[snowborder714]

It could be blown ISC drivers, especially if you hooked up a non-working ISC to the plug, or if the plug/wires were damaged. I'm not familiar with the N/T and their ECU, so I can't give any suggestions on how to go about checking it.

 

[haswesley]

Are you getting electricity to the IAC? The valve may not move just by turning the key on. The IAC is triggered by engine temperature and it closes as the engine warms up to operating temperature.

 

[NewToDSMCars]

I have tested the connector with a multimeter and it is getting juice but the signals from the ECU seem very weak no matter what I do it just revs up and up I don't want to leave it running long like that because I don't like 4500 - 5500 RPMs for an idle When I took the ECU out I could smell burnt electronics. I think I took on a bit too much for a project car with this one but I have always wanted a nice little DSM they look nice.

 

[awdtalon21]

Did you open the ecu and look?

 

[NewToDSMCars]

I did as much searching in the case of the ECU as I could but that thick red jelly doesn't help.

There are a lot of hacked wire harnesses in this car from what I can see. This completely hacked off and what not I pulled up the center console and there is a wire harness cut off in there my guess is maybe it was a auto to manual conversion and that was the transmission control module harness. it was all cut off and tapped up and wires touching that poor ECU

 

[NewToDSMCars]

Guess I will just try a new ECU as the one I have just seems to be no good.

 

[tburch]

Did you ever locate your problem