After doing some searching in this forum and others, my idle is still high upon start until it gets warm (and started again). Idle is around 1800 cold start in P and N and in any driving gears it slows down to around 1200.

So this is what I’ve done so far:
1) cleaned TPS
2) replaced IACV
3) checked for Vac hose leaks
4) cleaned MAF
5) cleaned Throttle body

I am going to go ahead and change a couple vac lines that look suspect but I don’t think that’s the issue.
My next thing and what I hope fixes the issue is resetting adaptive values in my truck. From talking to people and searching forums it seems like the cheaper option to take it to the shop for this than for me to fork out a butt load of cash for a diagnostic that can do this.

has anyone had any luck with the android app for GEMS to reset adaptive values?

 

The problem here is the roof rack. You need to remove it and ship it to me for long term observation. I will mount it to the top of my D1 for the next couple of years and see if the same problem occurs.

Great lookin truck. How many miles on the ODO?

 

It’s got 180,000 well maintained miles. (Usually) runs very very well. Thank you!

 

How does the intake manifold valley gasket look - they usually don't cause the problem but they can if they have deteriorated and leak - also the plenum cover doesn't get a gasket just RTV and that can deteriorate

 

that’s a good idea to look at, I will check those out soon and get back to you guys. Should I remove the cover to check it all out?

 

if the vacuum hoses are ok - the plenum cover would be a next check - you can spray some soapy water around the base of the cover to see if you see any bubbles - if you do take off clean old RTV and reapply - the RTV

to check the valley gasket you will have to take off the manifold and you will need a new gasket handy as they can't be reused - like i said this would be more unusual to leak but if the plenum cover doesnt show any bubbles that would be next - not difficult to remove - just double check on the torque specs when you bolt down - I think its 28 ft. lbs but check and the tighten down pattern

let us know

 

I would quadruple-check the vacuum hoses though... Check the PCV. Brake booster check valve. Basically vacuum like the others have said. Hidden vacuum.

Maybe hose around a little with some propane to see if it sucks any in somewhere and changes operation. Then you can zero in on a location.

Yeah, very sharp looking rig!!! Love the vintage-looking tires too.

 

There is a procedure to set base idle on a 94-95 14CUX & 96-99 GEMS. It's in the RAVE Manual.

 

doyle, I think you are on the right track. Get the adaptive values reset before messing with all the other stuff. If the TPS gets repositioned to a higher percentage than baseline, that can cause the high revs you described. It happened to me. Very annoying. I have not used the app you mentioned, I rotated the TPS a bit CW instead. Problem solved.

I think stillruns is wrong though, it's not what's on top that's the problem, it's what's underneath. I'm sure that loverly Disco would run just fine sitting in my driveway!

 

The android reset worked well on mine. A worthy tool for your collection... Russ