High Idle

[blkvette85]

I have a '94 1500 with a 350. Changed some pigtails (IAC), now the engine has a high idle. I have the factory manual and according to the wiring diagram it is wiried right. I only changed the plastic part of the pigtail, no wire splicing.

I also changed the IAC after about 1500 miles. Still the idle is around 1500 rpm. I checked for vacuum leaks and did not find any.

Any ideas?

Thanks

 

[shelbyt.67]

Reset Iac

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run jumper, turn key on, do not start, let reset fer 20-30sec. Turn key off, remove jumper.

 

[blkvette85]

Thanks, I'll try that.

Semper Fi

 

[shelbyt.67]

OOO RAH!

 

[tscherbi]

Thanks for your service Men

 

[blkvette85]

I reset to computer, now it does not run when cold. I have to press the gas to keep it running. When it warms up it still idles high. I think the owner that had it before me may have messed up the wiring. He replaced the engine. Does anybody have a picture of the IAC pigtail? I looked in the FS and the wiring was off. But I am thinking the replacment pigtail marking may be off. I matched up the a terminal with the a on the wiring diagram in the manual.

Or, could it be possible my throttle body needs rebuilt?

 

[shelbyt.67]

Rebuilding the TB is never a bad thing, but I would try replacing the coolant temp switch first. The no run when cold/high idle when hot, sound very much like that switch. Its located on the intake to the left of the thermostat housing. like $15-$20 or so.

 

[blkvette85]

Thanks, I'll try that. I think I might also rebuild the throttle body. The truck is not an everyday driver. I use every so often to drive up to Ohio. So, I'm in no real hurry to get this done.