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Long crank time '03 6.0

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Even more graphs for you guys... First, the CKP wiring issue... This is from pin 30:

 

I apologize- I had a brain fart. My saved waveform is labeled "CKP pin 30 to ground idling" and shows a downward slope on the identifier.

 

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And this is from pin 30, after swapping pins 30 and 41 - this one is a "proper" CKP waveform:

 

 

Should we be worried about the noise in the center of the identifier where it crosses zero?

 

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Unfortunately, the truck requires an extremely long crank time to start, and it runs like shit. The tach also jumps alot at idle. So, I swapped the pins back. Evidently on this vehicle, the first CKP waveform is correct.

 

 

Now, the CMP vs CMPO at below cutout speed:

 

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And again:

 

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Now, just barely bumping cutout:

 

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And at WOT, so the cutouts happen more frequently and violently:

 

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And again:

 

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It looks to me like the CMP input is good. However, it is quite obvious that the CMP out is bad.

 

I agree, but I still might scope a known good 6.0 truck at WOT and verify that the CMPO stays small.

 

I did swap the FICM off a known good truck, per the field service engineer's suggestion, and it did not make a difference.

 

 

Also, the noise that we see/saw on the CMP line - it's still present with the battery charger off the vehicle.

 

Make sure you don't have a battery charger on when taking scope waves!

The alternator field and output are still disconnected. The noise is not nearly as bad when the engine is at KOEO, but still there.

I have scope waves of pin 30 to ground KOEO showing about 1.5v and wavering slightly, and pin 31 to ground KOEO showing .2v and wavering slightly.

 

Anyway, there you go.... Again, thanks guys....

 

 

Now I'm back with you thinking it's PCM.

 

Could there be a power or ground issue that was disturbed while the engine was installed? You don't have a BOB, right? Can you scope powers and grounds to the PCM easily, or is this time consuming?

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Hang on - the CKP identifier is supposed to go negative first, then positive - take a look at your 6.4L graph:

 

Posted Image

 

But, the noise in the middle, I don't know about...

 

So, the waveform being inverted is a red herring.

 

I noticed the CMPO dropping below 0V between pulses when the engine was going wild, too. The more wild the engine got, the more negative it went.

 

So, yeah - powers and grounds. An engineer will be here shortly (like within a half hour) to work with me on it. He's supposed to have the PTEC to 104 adapter, so scoping many lines won't be a problem. I'll have data on that later on.

 

I did the engine replacement(s) the same way I do all major engine work on these vehicles - cab off. I think it's pretty unlikely that there is an issue with loose or disconnected grounds; I've trod this road a number of times. However, I am not above double checking (or triple and quadruple) my work, so I'll go over grounds again before the engineer arrives. Powers come in from the left side battery, through the body harness, and then through the two connectors under the power steering resevoir. Those connectors were cleaned and checked prior to reassembly, since I'd been burned by that before on a really filthy truck - pushed dirt up into the connector during reassembly. Again, I'll double check that too...

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Heh, I guess I didn't read the first part of your message very well, Bruce - sorry about that.

 

Ok, so we're done with the slope of the CKP identifier...

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Larry, your post made me suddenly remember (no "old farts" jokes, guys) a steering column harness replacement (the short one that goes around the tilt mechanism to the multifunction switch). The apprentice replaced the harness and didn't check to be sure everything worked.... crossed wires right out of the box.... Naturally, the customer wasn't what we can call "satisfied".

 

I screwed the pooch on the alternator deal though.... check out my original thread on "5.4/5R110" in about a half hour.

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  • 5 years later...
  • 6 months later...

What was the outcome of this thread?

 

I spoke with Greg and he said:

 

 

New PCM fixed up the CMPO signal and repaired the long crank time.

 

It seems the PCM was altering the cam signal whilst tryiing to get to the FICM.

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