Why do you need a smoke-test?
Weird, at a loss. Need to learn how to test electrical circuits.....
- Thread starter Lou Merrell
- Start date
Lou Merrell
OBS Enthusiast
New compression (dry) numbers:
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Lou Merrell
OBS Enthusiast
Probably don't but I just want to make sure. Don't know how to read my numbers from the scan. I do know that my long term fuel trims improve with engine rpm.
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.
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
OBS Enthusiast
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
OBS Enthusiast
Timing chain shows 5*-6* of slack/stretch. That's five to six degrees.
I think I'm good for now.
I think I'm good for now.
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