Mine has a steady fast idle,making me think it's not vacuum leak. It started a few miles after driving 20 miles of badly washboarded dirt road crossing Carrizo Plains National Monument. It hangs steady after warmup at 1,400rpm.
.
Today I swaped ICS,
no change
Then I checked water temp sender,,,225 ohms with engine warm and running. That's alittle less resistance than specs., but should provide low enough to tell ECU that engines hot.
I unplugged terminal at sender and check engine light comes on after a minute, telling me that no wires are cracked and ECU is getting infomation from sender.
All vacuum hoses and vapor and egr solinoids are not cracked.
since the RPMs are real steady I'm thinking this is electronic,,,and that possibly the ECU board cracked with all the vibes on that road.
Late tonight I plan on swaping in a spare ECU.

Try a good MASS ... My 89 did this and it was the MASS.. I can send you a good mass if that will help...

Thank's. I'll try that. I have a spare that I think is good.
I carry an ammo can full of used electonic parts when I go in the back country by myself, which is how it always is,,,I carry a distrib, coil, igniter, tps, ECU, and a massair.

Hey Haz, if Dave doesn't need that MASS I sure can use it! As long as its for a 89 V6. I've been having major Idle problems and just recently was told by a mechanic to replace the MASS...so I've been looking for one as it is anyway...how much you want for it?

I have a few MASS's (is that a word... <img src="/forums/images/graemlins/notooth.gif" alt="" />..)..Anuff for everyone ..lol... I live where old Montys come to die ...Will be at Junkyard "X" theres five gen1's and a Sport I'll be plundering tomorrow if anything else is needed ...They get $35 at the yard ..So hows $50 shipped ..I'm sure I'll have heading to $10 to ship it <img src="/forums/images/graemlins/scared.gif" alt="" />..I'll even pull the one from my running Monty for you hows that ...?...

Captain Gear Box

Hazardous Toys inc

That sounds beautiful! Do you have Paypal? Thanks man!

I could also use the piece that is missing in this photo if you can find one.

Forum rules are images cannot be larger the 600 pixels on the longest side. We let that slide a little (800 max for me) but your pic needs to be smaller please.

Sorry about that, I'll get it figured out.

No worries. I figured you didn't realize there was a limit. <img src="/forums/images/graemlins/cheers.gif" alt="" />