97 2.3 misfire

[97rriding]

I have a misfire on the third cylinder when the engine is cold. But after the engine warms right up it'll go away. But even still after I really rev if up it'll miss for a second or two before it runs smooth again. It used to have the check engine light on but it's turned off on its self now. I checked compression... It's a little lower then the rest but not that bad. After all it does run great after its warmed. I thought it could've been the injector so I took the intake off and switched that out but the problem is still there. I also did new plugs. (There's 8) I'm beginning to think this is a vacuum issue and it really has be baffled! I need help! Please and thanks


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[RonD]

Post compression numbers for all 4 cylinders.
"It's a little lower then the rest but not that bad", not that bad??

1997 2.3l has 9.4:1 compression ratio, I would expect 180+psi even cold.
Compression test should be done with one spark plug removed from each cylinder, and the throttle opened

Could be a valve train issue which happens with OHC, or valve issue lowering compression.
And yes it could come and go, as you describe

Fuel
Spark
Compression

These are the big 3
You have pretty much eliminated fuel and spark as the cause.

Unless vacuum leak is at the intake gasket for #3 then that wouldn't cause single cylinder misfire.

 

[Kenneth S]

What about the plug wires? New, or still the same old ones?