I drove the truck all day, it died while I was emptying my dump trailer but the low fuel light was on and I was pointed downhill so I figured it caught a bubble. Leveled off, added fuel, and it fired after a few cranks. Put another couple hundred kilometers on it, stopped for supper and now it wont fire at all.

Lift pump (air dog 2) wasn't coming on with key--would that kill my CP3 with a few hours driving?

Hotwired the lift pump, lots of cranking, no difference. Cracked a couple of injector lines at the head, cranked, got fuel there, still no fire.

Has a TS MP8 no other programming. Injectors and engine have around 4000 kms and CP3 got the bag-o-parts about the same time.

Help??


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I am here: http://maps.google.com/maps?ll=53.532121,-113.617618

 

Pulled all fuses--no issues. Cranks great. How would I confirm the ECM is getting ignition signal?

BTW it is in a 2003 F350 with the Destroked kit and the Painless wiring kit


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I am here: http://maps.google.com/maps?ll=53.532250,-113.617932

 

My next step would be to test for adequate Rail Pressure. On Common Rails cracking the fuel lines to look for fuel doesn't tell you much, if the Rail Pressure doesn't reach the set pressure for the Rail Pressure Sensor (on top of the Rail) the Electronic Injectors won't receive a "fire" signal form the ECM. You will probably find a leaking Injector or maybe even a leaking Rail Pressure Relief Valve (also on top of the Rail next to the Pressure Switch) allowing the Rail Pressure to drop below the amount needed to fire the Injector. The easiest test is to find an Injector Line Capping Tool. I bought mine from Hoelsi Deisel (Tester,Injector ISBe (Common Rail) 3164325 $57.16) Here: http://hoeslidiesel.com/store/page13.html. Any Dodge Deisel mechanic/shop will have one, maybe you can rent it or ask them to perform the testing.
The easy process is to cap off each Injector Line one at a time and then try to start the engine, it will start on only 5 good (non-leaking) injectors. Once you cap off the leaking injector the Rail Pressure will rise enough to satisfy the set pressure at the Rail Pressure switch and the ECM will tell the rest of the injectors to fire. Other possibilites include re-torqueing the Injector tubes which carry the fuel from the Injector line to the injector body, the perfect time to do this anyway is while the injector line is removed for the capping test I think they need 43 ft lbs.).
There are plenty of posts on this site with the actual step by step fuel volume tests to more scientifically test for leaks.

Good Luck!

 

What I don't understand though, is if the rail pressure is not getting up where it needs to be then what changed? I was towing 12K with it all day, it ran great and had good power. I parked it, came back after supper and it won't fire. I have a hard time believing that any hard parts failed to cause insufficient rail pressure.

 

in a nut shell, that is what happens to these silly things.

i have read every post on no start sence i bough one, he is on the right track to locate you problem.

if you have access to a scanner you could see what the computer is seeing. it must have 2000 psi cranking to fire

 

I had exactly the same situation once where I was towing a 10,000 lbs trailer with my GMC 6.2 diesel at 65mph for a few hours. I pulled into the rest area and turned the truck off immediately without giving the engine time to cool down. After coming back out and starting the truck it had a horrible knock and blowing white smoke as I re-entered the highway. I really thought I had blown the engine due to the knock and what seemed like obvious burning oil. After an overnight at a motel and a $700 tow I tried to start it and troubleshoot and low and behold it started right up and ran fine.

What actually happened was that by actually shutting it down so quickly after a hard tow the injector(s) had stuck open and were pouring liquid fuel into the cylinders causing the hydraulic knock and white smoke. Once The engine cooled completely the injector(s) freed up and closed allowing the engine to run correctly.

I am going down this "stuck injector" road because your posts states that you were pulling 12k lbs and shut it down for the night With a Common Rail, a stuck injector with cause low Rail Pressure and not let it start at all vs. starting with a knock and oil smoke like my old GMC 6.2 did.

 

I let it run until the EGT's were under 325, but that's something to keep in mind.

I hooked a code reader up this morning and it won't link. I also have no GPR and FP relay.

 

Remove the MP-8 completely, then try it. If a no go, remove the banjo bolt from the pressure relief valve and check for fuel. If fuel is present, attempt to start the engine and see how much fuel come out. If a lot, there's your issue.

 

Check and check. The PRV had fuel in it but I dried it and it stayed dry. Also pulled the FCA, dismantled, cleaned, and reinstalled. It had been cut btw. I'm getting a rapid education on these beasts.


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I am here: http://maps.google.com/maps?ll=53.571105,-113.858326

 

Replaced the ECM with one from a wrecker. Lift pump and GPR now come on properly, but other than that no change. I found the engine to chassis ground cable was MIA so I made one from 000 welding cable and installed it. Might be the reason for the last ECM death.

Installed a rail pressure gauge and fuel pressure gauge. Fuel pressure at CP3 inlet port (I got the extended banjo bolt from Cummins with the 1/8NPT port in the top) is 14-16 psi.

I temp wired the rail pressure gauge to the battery so it would read while cranking, and it takes two-three revolutions to get above 5K psi then bounces around between 5-7K.

Re-checked PRV after all that and it still doesn't have fuel in it.

Next step is look at the injectors? Hard to believe it would run great and then just die if the injectors are responsible

 

Not sure what it's called, but I used the plug from Cummins to block the injector lines one at a time. No difference on any of them.

Used a little propane into the intake (grid relay disconnected of course) and it would fire on that. Interesting part is now without the propane it will fire for a second and immediately die again, but only if I turn the key on and crank immediately without waiting for the grid heaters. If I wait, it wont even fire. Also interesting is that rail pressure will build up with each crank but as soon as it fires the pressure drops right off again.

Is it reasonable to think that the engine won't even run on an ECM from another truck? As I said earlier, I know this ECM made a difference because I can now read codes and my lift pump relay and my grid heaters come on.

Some input would be nice.

 

Following up.

It was the ECM, the new one I got happened to be from a SKIM equipped truck, which is why the truck would not start. I sent it to AutoWorld and Dawna flashed it for me to remove the SKIM module. Truck now runs great.

It's uncommon for an ECM to go out, but mine was toast. Still need to follow up and confirm the cause.