LMM: A member is broke down need help

blk smoke lb7

<-----Lots of green $
Nov 8, 2010
5,694
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belvidere,ill
had injector knock and switched injectors to see if the knock moved and it did swaped in a new injector and the truck cranks but wont start.The fuel rail sensor shows 17,000 with the truck off and if you unplug the rail sensor it shows 29,000. WTF?

Please any help or ideas would be great.
 

coker6303

Keep Calm and Chive On!!
Aug 6, 2009
2,484
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Houston, TX
Thank you Scott, I appreciate you hunting down solutions.

This is my poor truck. Left today to go to Ennis and hit the drag strip tonight to run slicks (thanks to Everett) and see how far we could push the ol' girl. Changed fluids in all of the drive train, loaded up and stopped to grab a bite to eat. Remembered the gopro at the house, turned back around and as soon as I crossed the road I heard a knock. Realized it was an injector and drove it back the 1-1.5 mile trip to the house. Pulled the injector, removed the tip, cleaned it and still knocking. Pulled it again, assembled it with my tip and a spare injector here at the house and then I couldn't get it to fire.

Went and bought a new injector, swapped tips and stabbed it to make sure (even though the truck should run on 7 injectors) but it just turns over.

Here comes the strange stuff. The actual rail psi is reading a constant 17.9k, and if you unplug the sensor it reads 29k.

Of course, I had to wiggle the injector on the passenger side as I changed the injectors out. So I wiggled them again looking to see if the rail psi on the scan tool changed, nothing... Pulled the plug off the sensor, 2 of the 3 wires are reading right at 5 volts (which is correct for input).

Can anyone verify the volts on the wires of the FPS?

harness has sense been unplugged and reconnected to see if maybe there was an issue at the ECM and the other 2 connectors over the driver side valve cover. No luck.

I have spare LBZ a couple hours away that I bought for parts, I will grab the FPS and whatever else yall can think of that may help.

I hate electrical issues! I could completely understand if something mechanical failed, thanks to JoshH and the tunes the truck gets driven like it's stolen everyday :woott: This issue is just frustrating! :mad:

I'm missing the races in Ennis!! horrible!!!!! :(
 

coker6303

Keep Calm and Chive On!!
Aug 6, 2009
2,484
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Houston, TX
ok, getting codes now. Showing a P0659 (TCM communication), P0193 (fps high voltage) and U0106 which is a bus connection issue I believe.

Any ideas???? I'm open to suggestions!! :confused:
 
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Burn Down

Hotrodder
Sep 14, 2008
7,092
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Boise Idaho
Not sure on your no start... But you can pull one fuse at time until the cable stops arcing at least it would give you a circuit to be looking at...
 

beanpole209

New member
May 5, 2010
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Id probably start by swapping the fps, & clearing codes, since you have another one. I'm not sure if that would prevent the inj's from firing, but maybe its just bad.
 

coker6303

Keep Calm and Chive On!!
Aug 6, 2009
2,484
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36
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Houston, TX
Going to start chasing grounds tomorrow.

This has been very frustrating!! But everyone once in a while you have to take your turn of bad luck.

Thank you to those trying to help!
 

coker6303

Keep Calm and Chive On!!
Aug 6, 2009
2,484
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36
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Houston, TX
So far the grounds look good and ohm out.

Plugged my ECM into another LMM, works just fine so the ECM is not the issue.
 
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coker6303

Keep Calm and Chive On!!
Aug 6, 2009
2,484
0
36
40
Houston, TX
key is in the run position.



sorry for the poor video quality, took it with my phone to post it up easily. The volts are correct, i get just under .6 coming out of the sensor down the harness.

[YOUTUBE]SXYjkV9Dp_k[/YOUTUBE]
 
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Schwinn68

little gearhead
Jan 9, 2008
632
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Minooka IL
Did you check all the pins in the bale connectors? Sometimes they can come just loose enough to not engage and cause trouble.