So the story goes I washed my motor like I have for years and now my idle is at 1500rpm. I went right to the forums to research what's up. I took the iac out and cleaned it and upon reinstall of iac the rpms went up to 3000rpm and then would almost stall and back up to 3k. So I bought a new iac from roverparts.com put it in and now it idles at 1250. I've done the reset for the iac valve with the Ignition on and off etc etc. I've been told I need the ecu reset? I pulled the tps off for the hell of it and with the tps plugged in but unbolted from the intake and the idle drops to 700 perfect! I put the tps back on the intake and it raises back up to 1250ish. I can move the tps before the bolts are in and make the rpm fluctuate. So my question is what do you guys recommend? A new tps or go to a dealer and have them "reset" the ecu? Thanks

 

I know Ive seen youtubes on how to diagnose a bad TPS but it requires more than a just a meter i believe.

 

When I had high idle I tried everything to fix it short of getting the ecu reset. Mine would run 1500 rpm at idle. If I unhooked the TPS it returned to normal. Local dealer wanted $150 for a reset and the closest indy shop is hours away. I ended up buying a used engine ecu and paired alarm ecu from Paul Grant. It fixed my problem and ended up being cheaper and I've had normal idle for almost two years now. I took the old engine ecu apart and found a good bit of corrosion which I suspect was the culprit.

Contact info for Paul Grant;
paulgrant@mac.com
classicroverparts@gmail.com
http://stores.ebay.com/Classic-Rovers
203-770-1699