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My truck is dead . . . need some help here

I would check the alt. If it is to hot to touch it could be sending too high voltage to your truck and playing havoc with the electronics, or could be shortin out inside and playing havoc that way. if it is OK sounds like it could be crank position sensor. IDK for sure but sounds probable.
 
Well, I am going to pull the alternator at lunch, take in it in and have it checked for output. I am curious as to why it is failing.

Also, I checked on the cam/crank sensor. It is $50 bucks and I can one here today but I DO NOT want to go into trial and error with this truck. I have done that before and it is bad mechanics.
 
That seems like a very low fuel rate. Has the Optic Bump been done on it?

What is the idle timing and your TDCO?

Try unplugging the CPS and see how that affects the fuel rate and timing. The plug that back in and unplug the OS and see if it that causes issues. This should cause some codes.
 
buddy said:
That seems like a very low fuel rate. Has the Optic Bump been done on it?

What is the idle timing and your TDCO?

Try unplugging the CPS and see how that affects the fuel rate and timing. The plug that back in and unplug the OS and see if it that causes issues. This should cause some codes.
Click to expand...

It has been optically bumped, years ago.

I think my timing was 15-16 degrees.
 
In that case I would suspect the OS may be involved. Either the bump or some air bubbles you are getting.

Losing the CPS wouldnt kill the truck.
 
I thought the cps "told" the IP when to inject fuel. Correct me if I am wrong. Not being a S/A just trying to learn.
 
The CPS is used in conjunction with the OS to detrmine timing. The OS sees the IP shaft driven by the camshaft gear connected to the crankshaft gear via the timing chain. They compare values. The truck PCM will function off of one or the other, although I believe it is weighted more on the OS.

How would the PCM know if it was missing crank counts if it didnt have two sources?

The OS will kill the truck if it sees air and it may cause it to loose counts, air can cause a lot of funky things and ghost codes and send people on a goose chase. That or if the fuel is too dark I suppose, but then the PCM should just use the CPS input for timing and not kill the truck.
 
I went home at lunch time and the truck once again fired right up.

I let it run and the truck once again just purred like a kitten.

After 6 minutes, the truck just died.

No start after that.

And no codes.

What should I try with the OS (optical sensor)???
 
try unplugging the OS and see if it starts. open filter manager see if any air come out of it. Is the PMD on an extension harness, have you tried eliminating that?
 
I did open up the filter "air bleed" and there was no air.

I also unplugged the OS and it would not start.

I have a harness extension, I am going to check that, good idea.

There is something weird though. Why would it start up fine, run for 5 minutes and then just die? It is like as the engine heats up, that is what kills it.

If the IP were bad, it would not start right? Or could it be a heat thing with the IP?
 
You can unplug the Engine Coolant Temp (ECT) sensor (aka CTS) if you think it is related to warming up. Thats the one on the thermostat housing. Then it will think its cold and get max advance.

Also, you can go back to the CPS and unplug that, as long as the OS is good truck should still run.
 
Matt Bachand said:
When it dies and you crack your bleeder does it hiss?

YOu say 7 psi at the pump, you mean at the IP or LP?
Click to expand...

I have 7 psi at the "T". Also, if I pull the Fuel Shut-off Solenoid and turn the key on, I have fuel shooting out of the IP.

ALL GOOD SUGGESTIONS GUYS!

I am going to pull the ECT and let it run.

I will also pull the CPS.

And I will take off the PMD extension.
 
Chicago TDP said:
I have 7 psi at the "T". Also, if I pull the Fuel Shut-off Solenoid and turn the key on, I have fuel shooting out of the IP.

ALL GOOD SUGGESTIONS GUYS!

I am going to pull the ECT and let it run.

I will also pull the CPS.

And I will take off the PMD extension.
Click to expand...

FWIW when I have a clogged liftter mgr fuel filter, i get 7 at T-valve, and 2 at IP inlet (enough to spew fuel), but instantly drops to 0 when applied throttle.
 
I'm sure you checked but, Any noticable fuel leaks ? I'km experiencing a simlar problem on my 94 which I believe to be the FFM leaking.
 
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