[attic.505]

Hey guys I apologize if this information is in the form. I did do a couple of searches and found a lot of information on results of running a compression test but no exact details on how to actually run a test. I never done this before and I'm planning on heading to AutoZone to rent the tool that way I can do this. I have a 360 1990 four-wheel drive that I just did a transmission rebuild on and it just feels like it's running really weak. Takes a couple of times to start it but once started runs just fine and idles perfectly. No engine codes except for the basic.

Thanks guys I also removed the catalytic converter but I'm sure that has nothing to do with my issue. Just needed to know the exact process on how to run this compression test properly.

 

[comrade cheddar]

  Warm engine, all plugs pulled, disable fuel (pull the asd or fuel relay) , prop open the throttle body and finally have a good battery that can spin the engine consistently through the entire test. You are ready.
  Screw the tester in and crank it a few times. If you can watch the gauge you will see it climb and level off. Record the results then wash and rinse 7 more times.
 

 

[attic.505]

Excellent, thanks Cheddar. I'll just the test results as soon as I'm finished.

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[attic.505]

Ok, finished results. We do have a lot of blow by on the spark plugs
1 115psi
2115 to 120 psi
3 115 psi
4115 psi
5 115 psi
6 115 to 120 psi
7 115 psi
8 115 psi



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[attic.505]

However these guys look like this.
Do you guys think this small block is just tired and old?

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[attic.505]

Tapatalk still being difficult with pic uploads.

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[comrade cheddar]

The numbers are a little lowish but nothing that will keep the engine from purring.

 

[attic.505]

Ok, excellent. I am going to be doing a deep clean today and tomorrow. Run through my grounds and double check hoses. It has sat for about two years. I have an o2 sensor I'll replace. And check electrical connections.
I'll keep you posted.


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[712edf]

Have you checked the timing chain to see if it has stretched? This could throw the valve timing off & alter the compression a tad.

Bucky