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

[stutaeng]

Does this mean you have valve issues? Need to refurbish the heads?

 

[Lou Merrell]

Does this mean you have valve issues? Need to refurbish the heads?

Oh, yeah.
I was hoping to get through winter though. I'll see. The compression in the other cylinders all hold stated psi even though they're all over the place.

 

[Lou Merrell]

I love my truck, it's worth it!

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[Lou Merrell]

This was taken at Thanksgiving at normal operating temperature:

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[Lou Merrell]

Tomorrow, before I remove dizzy I'm going to do what Frank said and check the timing chain, good idea, thanks Frank!

 

[Schurkey]

You've done a leakdown test on the three worst cylinders? What were the leakage percentages? What does your leakdown tester show on "good' cylinders?

If this were me, I'd pull the valve covers, verify that the valve springs aren't broken...and then pop each valve tip (NOT the retainer) with a plastic-tipped one-pound hammer. Let the valves get smacked open an eighth-inch, and slam shut that eighth-inch a few times...then retest. Any carbon holding the valve(s) open will be crushed. The valves might seal again.

And since you've got the plugs out...heat the firing tips with a propane torch until they glow orange. Or just replace 'em. Make sure they're not fouled.

Distributor caps are a known problem on the '96-newer Vortec 5.0 and 5.7. Make sure yours is good.

Tomorrow, before I remove dizzy I'm going to do what Frank said and check the timing chain, good idea, thanks Frank!

How? You already know the distributor has excess play. How will you determine the chain is bad if the distributor / gear mesh is poor?

 

[VFJimbo]

Nice Truck....

 

[Lou Merrell]

You've done a leakdown test on the three worst cylinders? What were the leakage percentages? What does your leakdown tester show on "good' cylinders?

If this were me, I'd pull the valve covers, verify that the valve springs aren't broken...and then pop each valve tip (NOT the retainer) with a plastic-tipped one-pound hammer. Let the valves get smacked open an eighth-inch, and slam shut that eighth-inch a few times...then retest. Any carbon holding the valve(s) open will be crushed. The valves might seal again.

And since you've got the plugs out...heat the firing tips with a propane torch until they glow orange. Or just replace 'em. Make sure they're not fouled.

Distributor caps are a known problem on the '96-newer Vortec 5.0 and 5.7. Make sure yours is good.



How? You already know the distributor has excess play. How will you determine the chain is bad if the distributor / gear mesh is poor?

No, leakdown on all cylinders.
And.....point made on distributor.
I did the bym (back yard mechanic) leakdown test on all cylinders.
Cylinder at tdc of compression stroke with 10 psi of shop air supplied to cylinder through spark plug hole with compression tester adapter, listen to tailpipe, throttle body, oil filler, and just for good measure checking for air bubbles in radiator/reservoir.

 

[Lou Merrell]

Any ideas why I would not be having a MIL?
I'm using an Actron 9660 pocket plus and it's reading no codes.

 

[Lou Merrell]

Ok.
New dizzy in, she fired right up but I definitely need to set the timing.
Here's old distributor with .050 of vertical play and worn gears: