Weird, at a loss. Need to learn how to test electrical circuits.....

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Lou Merrell

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New compression (dry) numbers:
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Schurkey

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Your fuel trims are showing negative numbers. I'm not used to fuel trim being shown that way--my tool showed fuel trim as a number higher or lower than 128, with 128 being the middle of the 255-step range. Lower than 128 meant the computer was trying to lean-out the mixture, greater than 128 meant the computer was trying to add fuel.

I suspect negative numbers on your tool mean the computer is trying to add less fuel--leaning-out the mix. A smoke test is generally used to find vacuum leaks--but if the computer is trying to lean-out the mixture, it's almost certain you don't have a vacuum leak.

I suppose you could have a minor vacuum leak that's being covered-up by an even bigger in-manifold fuel leak. What are the chances of that happening?

Your compression test results look fine to me.
 

Lou Merrell

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Well, I definitely have (had) a miss/stumble/hic-up coming from somewhere. Although I haven't ran the truck since finishing the compression check, plugs, and wires today. I want to take the cap off the dizzy and check to see how much play/stretch I have in the timing chain before I button everything down and run the engine.
 

Lou Merrell

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Timing chain shows 5*-6* of slack/stretch. That's five to six degrees.
I think I'm good for now.
 
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Schurkey

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From one of the "sticky threads" in this section. (You had to scroll past it to post here.)

www.gmt400.com/threads/88-98-service-manuals.43575/

 
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