LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Need help with problem diagnosis.

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Old Mar 25, 2006 | 05:53 AM
  #16  
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Re: Need help with problem diagnosis.

No disprespect but your posts never include anything concrete that you have done. You just keep speculating this or that. How about actually doing something and then report back what you found.

You said you had to do compression before thanksgiving, it's the end of March and it still isn't done yet??????? In that time you could have had the heads off and back on.

As far as the compression test is concerned, why don't you do a leak down test instead. That way the engine only needs to be rotated by hand. Since you suspect the head gasket is blown or valve/pushrods are bent, it is the perfect test to find such a thing. You can worry about the slow starter later. If it does have a leak such as the gasket into the cylinder, the longer you wait to fix it the worse the problem gets. Therefore, the higher the cost to fix it.

Drain the fuel into antifreeze containers and take it to the recycle center at AZ or advance. Be sure you put some old oil in it to darken it up.

A speculation on my part is this:

Head gasket blown (shows up easy with leakdown test) do a coolant pressure test to back it up.

You have a broken or burned wire between the ICM and the PCM.

Your battery is shot. You could always use the 24 volt trick to crank it over temporarily. Works great with the plugs out.

Don't take this the wrong way. Let us know something definitive so we can help
Old Mar 25, 2006 | 12:50 PM
  #17  
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Re: Need help with problem diagnosis.

, I appreciate your advice speedy but unfortunately it's not that simple. My time is limited, I have another car that I'm working on, and the problems I listed here aren't the only ones I am trying to fix. The car is also parked at my parent's house while I live 2 hours away. So it is kind of hard to find time to come down here and work on the t/a, especially since it takes ridiculous amounts of time to do any small task on that car. So please try to bear with me, I'm not trying to lead you on a wild goose chase.

I don't have a leakdown tester. I will see what I can do today and post something concrete later.
Old Mar 28, 2006 | 04:00 PM
  #18  
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Re: Need help with problem diagnosis.

Okay...

I tested the ICM terminals A and D on the connector to ground. I got 11.6v on terminal A but I got no voltage on D (the green wire).

I cranked the car with terminal B to ground and got A/C voltage fluctuating around 2.0-2.2 volts.

I checked continuity on the white wire from Black5 on the PCM harness to the ICM harness with both sides disconnected and got continuity. I also checked the PCM pin Black5 to ground and got no continuity.

On a side note, my Autometer tach is tapped into Black5 and it works perfectly.

What does that tell you Speedy??
Old Mar 30, 2006 | 02:50 PM
  #19  
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Re: Need help with problem diagnosis.

Speedy? Anybody?
Old Mar 31, 2006 | 05:12 AM
  #20  
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Re: Need help with problem diagnosis.

Sorry, with spring time in a mower shop, I'm like a one legged A$$ kicker.

I'm concerned with the fact that you are only reading 11.6 at the coil. This would be an indicator as to why you can't crank it fast enough. Ask me about charging Optima's with a conventional charger.

It appears your IC signal is good so let it be for now.

First you must diagnose the mechanical problems. Doesn't matter what the electrical does. After that little over reving stunt, anything other than mechanical should take a back seat.

GET THE LEAKDOWN TEST DONE! PERIOD

Follow that with pressure testing the coolant system.

If that turns out ok, then we'll move on.
Old Mar 31, 2006 | 02:38 PM
  #21  
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Re: Need help with problem diagnosis.

But listen, before I diagnose any mechanical problems (which I am starting to believe do not exist), why is terminal D getting no voltage??? It is not supposed to be that way.

I don't have access to a leakdown tester, but I can do a compression test and I can put compressed air into the cylinder. I should be able to tell if there is a leak and where the leak is at without a leakdown tester.
Old Jun 13, 2006 | 02:59 PM
  #22  
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Re: Need help with problem diagnosis.

It turned out to be the comp r lifters... I can believe that this incident that messed them up happened such a long time ago and none of them failed, they just kept hanging on by a little hair until now. All of them had pits in the little gold clips they put.

I know my car is fixed because if I powershift into third or fourth the clutch slips like I'm doing a standing burnout. Woo hoooo!!!!
Old Jun 13, 2006 | 04:06 PM
  #23  
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Re: Need help with problem diagnosis.

Glad you got it fixed.
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