your thoughts on this?
A friends truck... and he tells me, "problem all began when / after trying to jump start another vehicle"...
What I found is: this truck wants to idle fast. It's not the idle air valve. It already got a new one, and I've even tested the old one. Any vacuum leaks I believe are minimal. The computer is just trying to maintain idle at 1000+ rpms. There is some wear in the throttle shaft. I took advantage of the throttle stop screw to try to lower the idle, and left the idle air valve fully closed and unplugged. It's at least drivable now. With the IAC connected, the computer keeps the idle too high. If I force the throttle to close further to drop idle, the iac data starts climbing up to around 10 and idle is back to too high. If I put the truck into drive, rpms drop to about 650. Then IAC number climbs on up to 80 to 90%, tryiing to reach this high idle while in gear. That's a lot of added throttle, and not a good thing here in NH with snow on the roads. Either the rear wheels are a spinning, or the front wheels are a skiing! With IAC number that high in drive, when you put it back into drive the rpms go up to like about 3K before the number comes back down. My conclusion is the computer got damaged?? I know that's not typical, but this thing is crazy! All data, including coolant temp looks fine. What else would make this thing try to idle so high when in gear? Truck has A/C but it doesn't work. Data shows A/C OFF. AFAIK, there is no power steering switch to up the idle...