Problem on the 'limp' home yesterday.

[RichLo]

Can you read Knock count?

 

[Lou Merrell]

Can you read Knock count?

I'm not seeing that pid in dash command and no knock codes.

 

[Lou Merrell]

I assume this is it.
I can read it now.

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[Schurkey]

I still dont like that -24 degrees ignition timing... why is it pulling so much?

Pulling timing? Or just that scan tool's way of saying the timing is 24 degrees advanced? (i.e., 24 degrees before TDC)

I still want to know WHICH cylinder is causing the misfire.

 

[Lou Merrell]

Other than what the scan tool is showing, how do I tell where the misfire is coming from if spark and compression is good? Maybe spark/fuel isn't consistent? But then why doesn't it act up when the codes are cleared??
I'll see more when I check the injector pulse balance tomorrow or Friday depending on when the tool arrives.

 

[Lou Merrell]

On my way outside for injector balance testing. Will post results.

 

[Lou Merrell]

Results:

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[Lou Merrell]

Pressure held a 48 psi for 10 minutes before I releived it so that issue is resolved.
Thanks to stutaeng for the tip on the Allosun tester.

 

[Lou Merrell]

So, where I'm at now.......
Waiting on cats and need to repair downstream O2 sensor bung.
I'll bring #1 to tdc and check the rotor tomorrow but I don't think it has move because that would alter my cmp angle which is 1.1 to 1.6 degrees.

 

[stutaeng]

Those injector drop pressures look fantastic. You have to do system of elimination. You can almost certainly eliminate injector causing a miss at this point. Edit: but isn't static fuel pressure a bit low? I don't know what the minimum fuel pressure is for the MPFI...

My 5.7 Vortec was around 55 psi, on the original spider and after I changed to the MPFI. My 4.3 Vortec original spider was also around 55 psi.

Now you can focus on other possibilities. Ignition/spark? I know you said distributor was new. Maybe it's faulty? On the distributor though, not sure how one would check that?