Engine Misfire in V8 mode

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BG1988

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before you unplugged the injector, did the plug come out wet or more black then the others? that could mean the injector. and unless its tapping, I don't know that it's valve train.

did you do that compression test? I don't really know how you'd do that in a hybrid without maybe a tech 2 to engage the starter.

I would go to a auto parts store, buy one brand new acdelco plug and put it in there. that it runs smooth for a bit makes me thinks it's probably spark related still.
i see lots of sparks when i ground to chassis (using jumper cable) so it doesn't jump to hybrid stuff or anything else
 

j91z28d1

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i see lots of sparks when i ground to chassis (using jumper cable) so it doesn't jump to hybrid stuff or anything else


sparking in the air is pretty easy.. you can have cracks in the porcelain or even something called carbon tracing in the plug you can't see, and when the cylinder pressure gets higher, it will jump to ground before reaching the tip to light the fuel.

just some stuff I've seen happen over the years. got a miss, basically put some plugs in it and go from there. they are disposable wear items.
 
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BG1988

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sparking in the air is pretty easy.. you can have cracks in the porcelain or even something called carbon tracing in the plug you can't see, and when the cylinder pressure gets higher, it will jump to ground before reaching the tip to light the fuel.

just some stuff I've seen happen over the years. got a miss, basically put some plugs in it and go

I did a compression test it's only 0-3 psi So the lifter valve is stuck wide open...
 

j91z28d1

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I did a compression test it's only 0-3 psi So the lifter valve is stuck wide open...


if you can pull the valve cover. you might find a broken valve spring. much eaiser fix than a lifter

if it is a stuck lifter, what are you going to do? they usually tick like crazy when stuck.
 
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BG1988

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if you can pull the valve cover. you might find a broken valve spring. much eaiser fix than a lifter

if it is a stuck lifter, what are you going to do? they usually tick like crazy when stuck.
mild tick
 

j91z28d1

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definitely going to have to pull a cover to inspect it. were you still using the 4cyl odb2 plug thing? any chance it went into 4cyl mode?
 
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BG1988

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definitely going to have to pull a cover to inspect it. were you still using the 4cyl odb2 plug thing? any chance it went into 4cyl mode?
yeah it did a few time forgot to plug it in
 

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