Haven't had a chance to mess with the car much since I posted this but I got in it today and it reved to 3k and sat there. I now have a check engine light. Had that checked and it came up with TPS failure. Ordered a new one. I will hold off on the rest of the above suggestions for the purpose of problem isolation in case anyone has this issue going forward.

 

Changed the TPS and all was well for a while aside from a bit of jerkiness (as if running out of fuel). This has been increasing in frequency since the new TPS was installed. (Things were fine for the first couple weeks).

Yesterday it started acting up again. Revving way up to 3,400 RPM in neutral. It's been raining the last 2 days. Not sure if that's related or not.

I had meant to do the ECU mod before now but hadn't gotten around to it until now. Figured it might help but no change.

Bad TPS again? Thoughts?

 

Been reading around the forums and it sounds like my ECU might be crapping out. It got wet a few months back when a "buddy" of mine was driving it.

Does this sound like an ECU issue to any of you? I'm pretty skilled at soldering so I'm going to try and repair it myself.

 

High idle could be due to a idle air control valve also.

 

To 3,000 RPM????

What all does that entail? I can try that first.

 

I had a case where the wires to the ecu to the iacv wasnt pinned correctly or loose and it caused the iacv to stay completely open. the car did idle close to 3000 rpm. Ive seen another car with a completely shut iacv so the car wouldnt idle unless the i kept my foot on the throttle.

 

I pulled the IACV yesterday and apparently on the 97+ models you cant clean or do any maintenance on the IACV at all. I tried to clean what I could see which was not much and it made no difference.

 

Still having this issue. Daily driver and I have to get this fixed. Not only is it mechanically horrible for the car but it is consuming a ridiculous amount of fuel.

 

Ordered a new TPS hoping the one I had was just a POS. Long shot but that's the only thing I've done that seemed to have helped.

 

Hope it works out for you.

 

really sounds like an ecu issue, it would do that if the ecu has gotten wet and the caps go bad very fast. open up the ecu and take a look at it is the easiest way to know if its bad or not. If its not the tps and you have no check engine light codes coming or you can't read them then its worth a look inside the ecu.

 

Opened the ECU and all looks well. No signs of bad capacitors or water damage of any kind. It was fully sealed when I pulled the cover off. It was actually quite difficult to pop the cover. I had another TPS overnighted and ended up receiving the TRAC sensor instead so they sent another which will be here Thursday. I'm really hoping I just received a bad component.

 

Replaced the TPS AGAIN and the problem persists.

To recap:

TPS Replaced fixed problem temporarily.
Cannot clean IACV
ECU appears clean and when diagnostics run it seems to be responding
Still no check engine light

Any other ideas?

 

Oh yea, I have also done the Fuel ECU mod.

 

im Pretty sure its the ecu but i think i have 2 bad ones so just my luck.