DmaxEter

The truck in question here is a 2005 with a NV trans. It has had the Bully Dog with Crazy Larry on it, but that made no difference. When the truck is cold, it cranks and runs like a brand new one. I guess it should as it only has 26,000 miles on it. You can literally shut it off and try to start it again and it wont. It started out with long cranks at times. These slowly evolved into this problem here. It will only crank up good if it is cold! We cant figure it out to save our lives. It has been to the dealer and they said the injectors were bad. Pulled them and sent them to Dynomite Diesel and got them reworked and reinstalled. The truck still would not crank hot. Some one mentioned the CP3 not creating enough pressure to crank. Called up Industrial Injection and got a stage 2 CP3 with dual feed line kit. Called up Glacier and got a Walbro kit. The supply pump is set to 40psi. Spun the engine over for about 10 seconds and it fired up ran it a couple of minutes and shut it off, same thing, no start when hot. We let it set about 20 minutes and came back and it fired right up. We ran it maybe 5 seconds and shut it down and then it would not restart? Please guys help us out. This truck is driving us crazy and driving itself no where!! Thanks for any help.

53 willys

when you say the truck "shuts off" do you mean it dies or are you physically shutting it off?

DmaxEter

No, I mean when you turn it off by the key switch. It runs perfect except for this starting issue.

TexasCTD

Does the truck turn over (but not crank) after you turn it off, or is it just dead, dead?

Could it be a sensor on the clutch peddle?


Ironically, I never thought I would see you needing to ask for help on here with your diesel mechanic experience/knowledge. We usually have to turn to you. Good luck with it, Patrick.

DmaxEter

It turns over just fine, it just wont start. We are clueless at this point. The Dealer said it was not reaching the minimum required rail pressure to start due to the injectors leaking back. It has since hand an entirely new fuel system installed and it still does the same thing! Its driving us crazy!!!

Even the diesel techs get stumped at times. Its different at work cause when we have a problem like this, we get to get the reliabilty engineers involved and between all of us we can get things figured out. I dont get to call the reliability guy on this one though

J BODY

A: you need to monitor the rail psi and setpoint while cranking.
B: there are tests for the fuel return volume that may lead you to some
excessive return issues.
C: monitor the injector drivers when it's hot. Possible after "heat soak" there is an internal issue with the ECM. Injectors are supplied with voltage, ECM provides ground to "drive" them.

....all above would be best tested with the "toys" removed.

DmaxEter

Thanks. The dealer did some testing on it and said the injector return was excessive and that is why the injectors got sent to DDP. They did not correct the problem though. I would love to monitor the rail pressure but I dont have a gauge or line. Where can one get the line to measure that kind of pressure? I can get the gauges all day, but the line is my issue. I would rather have a manual gauge to test in the future with if need be. The ECM is the next option I think. I will rob the one from my truck and see what it does. When the truck does crank it does seem like the fuel system isnt primed. It starts to kind of fire and then it goes ahead and fires. When your driving it, it has several dead spots and falls on its face it seems at times. It acts like it is a fuel issue but my god. It has fresh injectors, a fresh dual feed CP3 and a new Walbro supply system. My only thought is maybe something inside the injector body itself causing the problem? Im not sure but I believe that DDP just removes the tips and works them over and doesnt mess with anything in the bodies? Is this right? Could the problem still be in the injectors them selves?

Thanks for the help so far guys, keep it coming!!!

deezilpwr

was the injector worked on a monday or a friday????????

J BODY

I would be a little apprehensive about swapping ECM's....especially if either truck is equipped with the SKIM security. I'm thinking if the modules see different VIN numbers you may have more troubles on your hands. Set point and rail psi can be read with the DRB scan tool. Not sure about aftermarket ones.

04ctd

i don't think it is a "heat soak" problem - where heat permeates something and causes a problem, like my lift pump Patrick replaced for free. it got progressively worse as engine temp went up.

I think is a pressure problem, won't a Triple Dog or Edge (or DRB3) read the fuel pressure via the ECM inputs?

if it looks like a pressure problem, isn't there a electronically controlled valve on the injection pump, and a "manual" valve on the fuel rail.

a "heat soak" problem would be investigated by using a heat gun to heat various items, and see when it won't run no more.

what is the difference on the "key on" momentary 30 second cycle, and the running signal to the lift (walbro) pump?

in other words, is the walbro running all the time, and have you tried 12v direct to walbro to eliminate that circuitry, relays, wiring and ECM management of that pump?

DmaxEter

Yes, the walbro is cycling correctly. It comes on and the system builds to pressure and then cuts off. When you hit the key it comes on and stays on.

I dont think its a heat issue myself. You can start the truck cold, run it for about 10 seconds and shut it off and try to crank it again. If it does crank you were luck and even then it will act lik it doesnt want to crank.

It also looks to me like if it were a fuel drain back issue then it would be hard to start when it was cold, after the fuel had drained back? This is right the oposite. Once the truck has been running is when it wont crank.

I am at a loss. I do know this thing has cost a lot of money and the dealers diagnostics were worthless!

MikeyB

Any error codes? Especially with the camshaft sensor? Check the wiring running next to the A/C compressor for any chaffing.

MikeyB

XLR8R

Mine behaves similiarly, though not as often and not as badly; I'd guess it'd be the crank sensor, as MikeyB suggested.

deezilpwr

i dont think a sensor cause if you touch a little either to it ,it picks up and runs and when i drive it, its kind of surging, and the power is not there.

04ctd

deezil, agree, the ether will cool sensors off, and the heat gun will test for heat resistance,

what year is your truck? post up ALL of your mods, and layout your troubleshooting (step by step) and symptoms after each change.

there's some smart folks on here, maybe one will peruse your data and find the culprit

FWIW, this is why i traded my 04 for the 06 in my gallery.

Patrick had one free part, but I could part swap forever, looking for a fix