2004 will not start
 

I recently acquired a 2004 3500 2wd w/ allison auto. It will turn over, but not start. Fuel is up to the filter. Pump the little hand pump until it is tight. I put my computer code reader on the thing, but I can't get a signal from the computer. Is there any way to tell if the computer is good without the port? I have tried 2 code scanners, but neither will come on with this vehicle, but work with my car.

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Oh, I just read the VIN and it is the LLY engine.

Replace the cigarette lighter fuse, the OBDII port draws its power from there. And see if you can get codes after that.

I got the scanner to work. cigarette lighter was shorted out. No codes. Everything says pass. I primed the fuel system, checked all the plugs I could, everything seems ok but it just spins over. The only thing I see that isn't right is the oil pressure gauge stays to the far right, pointing down and right.

crack injector lines 1,3,4 and prime it several times then tighten em up and try again.........should fire

New fuel filter yes? Does the exhaust smell like fuel at all when cranking, if so it could be an injector hung open keeping it from firing. one way to check that is to pull the glow plugs and turn the engine over and if they are hung open fuel will come flying out.

Can you observe the rail pressure while cranking the engine over with your scan tool?




u dont want to do that, and 1,3,4 are the hardest to get to with the engine and components fully assembled they're buried under crap

So another guy on another forum had a bad security circuit issue, and did a security "relearn". KNow anything about that? He said he didn't have a radio, put one in from a salvage yard, did a relearn and it started right up. And I have no way to smell the exhaust while I am cranking, it is outside, but I don't smell trace amounts of smoke when I get down there. This has the exhaust that dumps underneath in front of the axle.

heres a thread https://www.dieselbombers.com/chevy-...acing-ecm.html about the "relearn procedure" post #3

Did the relearn thing. Now how tight is the manual prime button supposed to get? Seems like it is now losing prime?? When I crank it, the button goes back to very easy to push like when you open the bleed screw.

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Oh, and still no start. Did not smell anything at the exhaust end of things. Don't know if it is getting fuel through the system.

I now see this is a Duramax................I thought you had a Cummins....sorry dude but scrap everything I said earlier

check all fuel connections for leaks. around the fuel filter and such

Guess I should do a signature, huh? All of the fittings for fuel are tight and dry from the filter to the injectors.

Could be a cracked fuel filter housing. Seen it happen quite a few times now.

NEVER CRACK A COMMON RAIL HP FUEL LINE..Whitmore knows this just didnt say it lol

I would not crack a fuel line on a dmax

when cranking over are you getting any smoke or fuel smell?
is the security light flashing?
do you have a scanner of somesort to check voltage at cranking?

I only have time to work on it at night outside, hard to see smoke. No smell. No light flashing. Have a scanner, but can't check voltage. If you are asking about batteries, I have two new batteries I just got. I will try to get the filter housings changed between pickups here in a day or so. Surely both can't be cracked. And what is wrong with cracking the lines? Or do you think a common rail system could do something with the little bit of pressure?:hurt:

the cr system will bleed it self anyway, ive replaced injectors many times and itl fire up with out bleeding the injector lines, just takes a while.

where you located? maybe some one with a good scanner can see whats goingon. try unplugging the FCA and turning the engine over, this will command 26kpsi. are all the wires connected and snug? check the number 5 and 7 injector harness make sure they are making solid connections, back two on the passenger side)

FCA?? Where/what is that? And i am in tulsa ok, don't know anyone here. I really wish I knew how to check the computer. The guy told me the other day the dealer said both needed changed.:ouch:

FCA / FPR the little electrical connection on the cp3.

Check the fuses in the panel under the hood. I had one blow and it would do the same thing just turn over and not fire. I cant remember if it was an ignition wire or one of those that say Injector fuse. Its something else on the diesel but cant remeber what. Test light or pull one at a time and check.

is it one of the gray square ones (breaker) or a fuse? I thought about that, but I don't know how to check the gray ones.

It was a 10 or 15amp fuse.

The gray square one is a relay, you can swap them out with eachother just make sure the terminals are matched up correctly

Air lock
 

This was back in 2009. And this was the LLY. What happened, was one of the injectors hung open. It wasn't allowing it to build enough pressure to start I guess. Anyhow, we used starting fluid to get it fired up, and it ran. Replace the injectors, and that was it.