I have been chasing a high idle for a while, I had also had a very difficult cold start but that was solved with an IAC. I thought I fixed the old one, but it fell apart again.
Doesn’t stall at cold start now, but still had a hanging idle/ high idle most of the time.
If I pulled the throttle blade fully shut it would bring it down. Hmm I have heard TPS issue can happen, I unplugged it and that actually made it drop! Ah ha! So I look for what a tps is supposed to read and mine is actually fine. 13.3% at close, red herring.
So I check fuel trims and it’s adding fuel, look at map readings, it’s at like 8-12 inhg, that ain’t good. So I get some starting fluid and start blasting. Checking a few spot and idle drops hard when I spray around the injectors and intake gasket. Wiggle the injectors a bit and that changes nothing, good because that rail is kinda crusty. Oop, for sure intake gasket leak. Dang. I don’t want to take this THAT far apart.
I grab a 9/16” box wrench, Lo and behold half the bolts are loose. This thing looks like it’ never been apart, but I think due to thermal expansion and the bolts doing double duty, holding both manifolds, over the pass 199,000 miles they have worked loose. The closer to the fire wall the looser they were.
So check your manifold bolts, they’re probably loosening up.
Doesn’t stall at cold start now, but still had a hanging idle/ high idle most of the time.
If I pulled the throttle blade fully shut it would bring it down. Hmm I have heard TPS issue can happen, I unplugged it and that actually made it drop! Ah ha! So I look for what a tps is supposed to read and mine is actually fine. 13.3% at close, red herring.
So I check fuel trims and it’s adding fuel, look at map readings, it’s at like 8-12 inhg, that ain’t good. So I get some starting fluid and start blasting. Checking a few spot and idle drops hard when I spray around the injectors and intake gasket. Wiggle the injectors a bit and that changes nothing, good because that rail is kinda crusty. Oop, for sure intake gasket leak. Dang. I don’t want to take this THAT far apart.
I grab a 9/16” box wrench, Lo and behold half the bolts are loose. This thing looks like it’ never been apart, but I think due to thermal expansion and the bolts doing double duty, holding both manifolds, over the pass 199,000 miles they have worked loose. The closer to the fire wall the looser they were.
So check your manifold bolts, they’re probably loosening up.
