- Thread starter
- #21
I'm thinking IAC-related as well. Stumped. Be nice if there was an 80 owner in my area I could swap parts with for a couple of mornings.
No More High Idle on Cold Start
- Thread starter harrydunn
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
- Thread starter
- #22
Here are a couple of videos. First one is what it does every morning when cold. 2nd video shows how it starts up the rest of the day when warm. As you can see in the first video, it revs up, falls on its face, then idles back up but no high idle when cold.
- Thread starter
- #23
Bump for the evening crew. Would love to figure this out before we hit really cold weather this winter. I'm not sure how it will react then on morning starts.
Install a hand throttle and use it to manually cock the throttle plate open a little before you crank it. Similar to using a manual choke that never misbehaved back in the day. You can have one for $57 shipped. I have owned two 1994 models in the last two years. My first one roared to life and hung there for what I felt was an unnecessarily long time. The one I have now does it to a much lesser degree and slows down much sooner. These old trucks are like women. Sometimes, if you ignore the situation it corrects itself.
- Thread starter
- #25
Yah, I suppose I will give it a few weeks. My gut tells me it's the IAC. I've located a couple and may just bite the bullet.
thatcabledude
GOLD Star
PM'd you
Had similar problem, cold start high idle to 1600-1800 rpm first 2min. Added rubber spacer on IAC, it helped by lowering to 1300- 1500rpm. Couldn't understand why Coolent temp sensor had anything to do with it, after a year of wasting gas, decided to give it go to replace temp sensor, it works! back down to 630rpm.
- Thread starter
- #28
We are definitely (hopefully?) down to the ECTS or IAC valve. Borrowing a known good IAC from CableDude. I want to see what that does and then on to the ECTS if necessary. Can't imagine what it would be beyond those two items since it runs like a champ. Just no high idle. They both check fine per the FSM but maybe it's an intermittent type of thing. I enjoy working on my rig so I can't complain. At least it's not something major.
alia176
SILVER Star
Good job on doing actual troubleshooting and not just throwing parts at it. I have VCI Techstream and I wonder if that'd give you any hints? Truthfully, I've never hooked it up to the 80, only to my 4Runner. I should play with it.
- Thread starter
- #30
Had some time today while I'm waiting on the test IAC to arrive within the next few days so I installed a new coolant temp sensor with no change. Putting all of my money on the IAC. I don't have a next course of action after that. I'm stumped. Took some time to rewrap my wiring harness by the EGR pipe with heat reflective tape while I had the hood open. Glad I did. The old insulation literally fell off as I was trying to get my hands in there. Tough place to work back in there.
- Thread starter
- #31
Normally don't rearrange the garage to fit four vehicles in it until mid-December but I'm curious to see how it behaves in a 65-degree garage upon cold start instead of mid-30's outside of a morning. Maybe that will give us some ideas.
- Thread starter
- #32
Well, gang. Known-good, borrowed IAC is in and same result-No high idle upon cold start of a morning. Going to leave it in a couple of more days to verify. Any other thoughts on this? I'm tempted to pull the TB and clean it again but it just wasn't that dirty. Vacuum leak, EGR valve?
Last edited:
LFD2037
TEXAS LEXUS!
Damn. Weird.
- Thread starter
- #34
Pulled the throttle body again and cleaned it to within an inch of its life. Every passage was blasted and then blasted again. Buttoned things back up, double-checked all vac hoses are hooked up and in good shape, adjusted the throttle cable, etc. We will see what we get tomorrow morning when cold. Thinking I should start an 80-Series TB removal and cleaning service out of my garage. 
- Thread starter
- #35
Well, I'm out of ideas. I suppose it is time to take it to my mechanic. I sent a video to them showing what it's doing. Ugh. They're a great shop, I just hoped to resolve this on my own.
- Thread starter
- #37
Thought about that but wouldn't I be seeing a host of other problems? I do have an idle lower than normal when warm. Not sure if that would be TPS-related or a vacuum leak. All of my hoses look good. Hard to see those under the intake.
I think this is the thread that had me thinking TPS might effect idle. But maybe i am looking at it wrong.
FJ80 High Idle Problem Solved
FJ80 High Idle Problem Solved
ChaseTruck
--
So, this may not help matters very much, but: our '93 doesn't do high idle. It probably "knows" we are in Baton Rouge, and so it never gets real-world cold; nevertheless, even on "cold" days (yes, some days it gets close to or even below freezing...) it doesn't, either. Yet, it idles smooth, normal throttle response, easy driveability. I've decided to worry about it when the ECU starts to worry outside temps...
- Thread starter
- #40
Interesting and thanks for posting. Has it every had the high cold idle?
