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idle help pls

1K views 19 replies 5 participants last post by  Common 
#1 ·
I have a 96 cummins 5.9l with a 5 spd rebuilt motor. I have the idle set at 1000 rpm but when I turn the ac on it idles down to 600. I know its not normal to drop that much how do I fix this problem and when I turn the ac off it wont idle back up unless a tap the pedal pls help
 
#2 ·
I would have the ac compressor tested.
 
#4 ·
Put in a 3k governor spring kit.
 
#6 ·
Are you positive that you removed all the shims? How far down did you tighten the retainers?
 
#7 ·
Yes all shims removed and i sent it a .050 and it was to tight so set them at 2 clicks and i can adjust the idle where I need it now but now its isles at 1k and when I turn ad on it drops to 6 00 I have had the governor springs apart 50 times trying diff setting and it seems to do the beat at 2 clicks in
 
#12 ·
Idle spring is the large outer spring in the stock spring set. Did you leave that one in or did you just put the springs from the kit in?
 
#17 ·
You're gonna have to mess with your idle adjustment.

Leave the truck running and start messing with the idle. I bet if you go a hair lower than 1000, it'll idle the same with ac on or off.

Mine did the EXACT thing yours is doing. Does it drop slowly to 600, then climb slowly back to 1000?

It's the springs causing it.
 
#20 ·
Back off a click on the springs, then try it again.

You'll find the sweet spot.

I can video mine.If ya want. Keep it running - remember, when you tighten the lock nut down on the idle adjustment you're messing with your adjustment, compensate for it. These things are touchy with springs.
 
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