Open request to help interpret TunerPro recorded log

[Scooterwrench]

If it is puffing smoke at fire up in the morning and/or when it has been idling for a period of time then those valve seals would be suspect. If the guides were worn the new seals would only be short lived.

 

[PlayingWithTBI]

1995 Chevy K2500 5.7 350 TBI with 4l60e trans. 131k miles.

What PCM Service Number are you running, the 7427? With A219 $OE TPS v250.adx your BLM looks pretty good (maybe a tad lean)

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But, while accelerating (light blue line), you're getting a lot of Knock Retard (green line) and your Spark Advance (dark blue line) is all over the place. Your TPS (red line) looks OK.

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When cruising, there's no KCs. You can see on the far left of the table KCs are going down, thus your SA is steady at ~20.

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KCs can be caused by loose exhaust, motor mounts, etc. Or, your Knock Sensor is bad. In a 94, your EST is internal in the PCM, hopefully it's not the issue.

Anyone else wanna chime in?

 

[Moss]

What PCM Service Number are you running, the 7427? With A219 $OE TPS v250.adx your BLM looks pretty good (maybe a tad lean)

Yes, the 7427 I think.

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So I should maybe start by checking exhaust connections from the motor and motor mounts?
Also, could I take a multimeter to the knock sensor to ensure it's functioning correctly?

Thank you!

 

[PlayingWithTBI]

could I take a multimeter to the knock sensor to ensure it's functioning correctly?

That reminds me, improper torque (~30 Ft/Lbs IIRC) on it can give you false KCs too. Maybe your FSM will help on troubleshooting it...

88-98 Service Manuals

Over the years I have collected a bunch of GM service literature. Links to PDF Scans of service and STG manuals and a links to the Parts manuals. You'll need the FREE Adobe Acrobat reader to open these files. Get it directly from Adobe here {http://get.adobe.com/reader/} If you're not...

www.gmt400.com

 

[Scooterwrench]

Piston slap?

 

[PlayingWithTBI]

Piston slap?

Or rod knock but, we don't wanna go there

 

[Moss]

Or rod knock but, we don't wanna go there

There was a ticking sound that we thought might be rods, and we manually adjusted the rockers which took care of the ticking.

 

[Scooterwrench]

Or rod knock but, we don't wanna go there

Rods normally get looser at cruise and would show up on the KS. Pistons slap harder under acceleration.

 

[PlayingWithTBI]

Rods normally get looser at cruise and would show up on the KS

IDK, I've had rod knock on acceleration and main bearings while cruising but, who knows?

 

[Scooterwrench]

Yes, the 7427 I think.

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So I should maybe start by checking exhaust connections from the motor correctly?

Thank you!

Have you checked the base timing? Maybe someone turned it up a little too high.