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1985 Chevy Silverado dieseling after shutoff?

With the high gas prices I have now switched my truck over to 87 octane regular. But now I am having all kinds of problems with dieseling after shutoff. The truck runs just fine on 87 octane, I just have the dieseling. The truck has about 103K on it (relatively low miles). Adjusting the timing really isn't going to solve the problem. I realize that dieseling is usually caused by carbon buildup in the cylinders. This is really getting on my nerves, any help is appreciated.

Reply to
Bill Blevins
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take a look at the idle speed.....to fast and it will diesel.

Reply to
Scott M

I honestly can't remember the last year they had an idle solenoid. If the solenoid sticks or had failed and the owner cranked in on the idle screw the truck will diesel when shut off. The solenoid is mounted on a bracket near the carb and has a plunger that pops out to control running idle. If I remember correctly, it also controls a faster idle when the AC is on. If your truck has one it could be the problem.

Reply to
JR

I think that is it. It is ideling a little too high. How do I make this adjustment?

Reply to
Bill Blevins

You may have an anti-dieseling solinoid on it (if its carbed)-simply adjust the hex headed screw-make sure yer regular idle speed screew is backed off as well. Respectfully submitted,

Loren Knighton Woodland, CA.

Under the hood since 1964 Member TRNI IATN

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Reply to
BACKNCARDR

Where is this screw on the carb located (yes it is carbed)?

Reply to
Bill Blevins

Near the base on the right hand side, just look around the throttle linkage you'll find it.

Brian

Reply to
NoSpam

Where is the regular idel screw vs. the solinoid idel screw?

Reply to
Bill Blevins

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