I haven't gotten much done.
Swapped MassAir Sensor today and no change. Of coarse the reason that sensor and Montero were in the yard could have been a bad mass...

Riight, man too bad. Keep us updated, I'm hoping a new MASS will do the trick for me.

Golden , you got fisrt dibs on Haz's good tester mass air. It's gonna be awhile before I buy any parts. I don't have to pass emmisions next month for lic. renewal , so I'll limp along for awhile.
Looking at the wiring diagram I see how one wire goes direct thru the MA and the ISC without going thru ECU. Maybe that spot(whatever it is) is where they burn out. I wish the FSM had a braekdown on the M.A. so I could try to test components. Maybe I could find some youngster with good eyes and a steady hand to solder new parts in.

got nothing done untill this morning cause I got fed up with Syphilization and head to the Mountain to hang with the Alligator lizards for peace and quiet.
Anyway this thing runs great down the road, it's just fast idle. So the Karmen Vortex part of the MAS must be working. I found the test in Vol. 1 FSM (not vol. 2 "electric" <img src="/forums/images/graemlins/confused.gif" alt="" />) for the air temp sensor part.
It has the right ohms at room telp., the refrigerator and in front of my heater duct.
This is probably something simple, just as I advized Goldenprospector,,,I just can't find strong enough coffee to make me fix it. I'd rather hang out in the woods.

lol...well thanks for the update. I'm still working on finding a MASS for mine, hopefully that will get everything back to normal. I hope you get it figured out soon...take care.

Dave, I think your priorities are just right.

thanks, mrray <img src="/forums/images/graemlins/cheers.gif" alt="" />
.
today I put my mightyvac to work,,,cheched EGR and Evap solenoids/system for leaks. Then checked brake booster hose and booster out. No problems found.
Then swapped in my spare ECM (takes a little doing on mine because I relocated it above the water line,,above and behind glovebox).
No change , idle pretty steady at 1,400 rpm as before.
Stumped <img src="/forums/images/graemlins/confused.gif" alt="" />
I stuffed some cardboard on the front of radiator to try to overheat a bit on the H20 sensor, but I don't have AC stuff blocking and it's a fairly new Modine 2 roll --it didn't get very hot.
.
Tomorrow I'm gonna start back at square one and buy a new 195o thermostat.

well Dave...so far I've changed the Thermostat, Throttle Position Sensor, Idle Speed Control, Water Temp Sensor, Throttle Body, Vacuum Lines, Brake Booster Hose, Mass Air Flow Sensor...

I STILL have a high idle!

I'm thinking about changing the EGR Valve next, then the ECU.

Somebody HELP ! What else could it be?

Did you ever contact that outfit that repairs ECU's to see what they said about high idle being a possibility of ECU failure?

Yeah Geo, I did call them. They pretty much made it seem like if it wasn't the problem now, it will be later. So if nothing else is suggested, I'll probably end up sending my ECU in to them.

Thanks again for the info.

Could it be that the timing belt is off by a tooth? but if this was the case, why would it idle at 750 "sometimes"?

Also, could a blown head gasket cause a high idle?