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Discussion Starter #1
My truck was running perfectly up until it stopped running completely. I have the CNC Fab stage 2 HPOP, Hydra, EGT and Edge CTS2 gauge system.

Suddenly one day when lightly accelerating from a stop my Truck suddenly shut off with no hiccup or anything seconds prior. I pulled over and pulled up the OBD codes. I had the code for the camshaft position sensor so I thought it would be an easy fix as that part is infamous for failing. I even had a spare unit on hand. So I swap the sensor and still no start.

I then pulled the truck up to my place to do further diagnostics. I'll do list format below so it is easier to follow:
  • IPR valve appears to be working but ECM is commanding up to ~34% while cranking
  • Injection pressure sensor also appears to be working as it is reading pressures that build up to 2,500 psi from the HPOP as it is supposed to do if you disconnect from the head and dead head the HPOP for testing.
  • HPOP is new performance unit and obviously healthy
  • ECM is commanding about 2.5 ms PW to injectors
  • RPM is reading around 160 while cranking
  • Fuel is flowing though I haven't tested pump side fuel pressure yet but will tomorrow after I borrow a gauge set. From what I can observe the fuel does appear to be building sufficient pressure but don't want to say certainly
  • Ran a buzz test and although I heard 8 distinct buzzes, every other buzz was faint as appears to happen when one bank isn't firing. The left side bank isn't firing at all. Right side bank is firing normally. No change if I try to crank with either bank unplugged.
  • Buzz test indicated P1293 and P1294 even though the right bank appears to be firing normally. Obviously have an electrical problem somewhere.
  • Reinstalled 2nd new CPS to see if it made any difference and it did not
  • Reinstalled original CPS to see if possibly it wasn't bad and maybe the code thrown is instead indicative of PCM issues. Original CPS appears to be working fine as RPM registers the same. Don't know if I can actually somehow plot the waveform with Forescan
  • No blown fuses or apparent bad connections or power distribution issues
  • Tested the connector side at the IDM and all the injectors tested out properly for resistance and no shorts or open circuits were indicated from IDM all the way to the injectors under valve cover.
  • When I crank I get the tiniest bit of white smoke out the tailpipe. Not enough to see in your mirror or from any distance away but if you are looking right in the pipe you can see some and smell it
  • Inspected engine harness at right bank valve cover which is common chaffing spot. Wires were perfect showing no signs of wear.
That's all I can think of right now off the top of my head but if I remember more later I will add. I only found one other forum post with someone having similar issues and it ended up being the persons PCM though it was an OBS if that makes any difference. Hopefully this is one of the more active forums left and if I ever solve this thing maybe help someone else out frantically scouring the internet all day for potential leads. If someone knows of a more active forum please let me know and I will copy my post there.

Though it could still be a wiring issue I'm getting more certain that it's either my IDM or PCM at this point based on all the diagnostic procedure results so far.
 

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P1293 and P1294 indicate IDM problems. If you have a known good IDM, try swapping that in.
 

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Discussion Starter #3
P1293 and P1294 indicate IDM problems. If you have a known good IDM, try swapping that in.
Currently trying to track one down to borrow. I plan on keeping this truck for a while and want to be reliable for longer hauls so if it turns out being a bad IDM I'd like to buy a quality reman or OEM over junk yard roulette. I definitely don't want to buy a $400 IDM just to find out that isn't the problem though.
 

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Discussion Starter #4
Tested fuel pressure and was only building 28 psi even though pump is capable of more if I restrict the flow. Pulled the cap off the fuel pressure regulator to find the oring fubared. I don't have the special tapered Oring on hand but just for testing purposed I threw a standard round oring in and was able to build 48 psi. Still no crank. So while this is an obvious issue it isn't what is causing my no-start condition exclusively.
 

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Discussion Starter #5
Ended up being a failed IDM. Threw in a borrowed known good IDM and she fired right up. In the meantime I have ordered a improved remanufactured unit from GB Remanufacturing. Couldn't find a compelling reason to pay twice as much for a high-frequency high-voltage upgraded unit.
 

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Thanks for closing the loop on your issue.
Glad you're back up and running (or will be soon).
 

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Discussion Starter #7
157724


Wanted to update with a discovery which is probably what caused my IDM to go bad. This issue caused a few intermittent issues with the new IDM where the engine would only run on the drivers side and almost left me stranded. The wires were covered in grime, tape, and loom so I didn't see this wire condition initially. Even though when I tested my IDM connection everything tested out theses bare wires must have caused a short every once in a while when the truck bounced the wires just right going down the road. Ordered a new pigtail and am glad I discovered this issue before wrecking another IDM.
 

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Man, that's ugly. Those wires would definitely cause problems. Thanks for the update
 
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