Cranks strong, won't start

[FWBDieselJay]

2001 Ram 2500, 5 speed, 4x4, 183k, 5.9 Cummins

 

i was going about 50mph after driving about an hour, I got a dead pedal intermittently for about 10 seconds, then the truck died.  It cranks strong, but will not start.  No signs of any combustion whatsoever.  Will fire off with a spray or two of ether but dies as soon as ether is burnt up.  

 

Codes: P0122, P1693, and heater grid code (can't remember the code number)

 

Filter bowl full of fuel.  Fuel filter changed about 3 weeks ago. 15 psi out of the lift pump.  Swapped fuel relay. Swapped cam position sensor.  Opened line out of ignition pump and have fuel when cranked. Opened line at #1 injector and have fuel there when cranked (did see some bubbling).  Disconnected LP wiring, and cranked, still have fuel out of ignition pump, which makes me think the injection pump is good. 

 

Im out of ideas.  Little help?

[Mopar1973Man]

Just because the VP44 pump is pushing fuel out the line doesn't mean its making the full 4,500 PSI to fire the injectors. Yes, it takes a minimum of 4,500 PSI in the injection lines to fire the injectors. So if you have a air leak on the suction side of the lift pump it will be enough to prevent starting or running. So first thing to do is check for fuel line leaks on the suction side. Be aware they never leak outwards. What I typically do is pressurize the fuel tank and 1-2 PSI and have a second person hunting along the fuel lines to find any leaks. Might be hissing air or fuel weeping out. 

[FWBDieselJay]

Ok.  Any suggestions on how to pressurize the tank?  I've never done that...

[Mopar1973Man]

Compressed air blow gun and a rag at the filler neck. Pretty simple.

[FWBDieselJay]

Thanks.  Will do.  I'll respond with results.  This thing has been killing me for about 3 weeks.  I appreciate your help. 

[kzimmer]

Did you just crack one line? I would crack 3, 4 and 5, crank for about 30 seconds, after seeing fuel on all three close back up and crank to see if it'll start. That's what I do when re priming. Still likely a different issue causing air but might rule out other problems.

[FWBDieselJay]

Yeah, I thought I'd just check one line to see if I was getting pressure up there. After all the troubleshooting and repair, I'm sure she's going to need a heck of a bleed job.  Thanks. 

[JAG1]

Need to check over your wiring and voltage too but I'd guess that You need the Timbo APPS. It's more reliable so  its money well spent in the long run. Next I would be looking for air sucking into the fuel like said above and check to see if your tank vent is working that your not collapsing the fuel tank. You can loose prime with a cracked factory filter cap too or not torqued to 25 ft lbs, but use the big socket not the center square with the 1/2 inch drive on the plastic cap or you can crack the plastic. A factory fuel filter cap that leaks air allows the fuel to drain back to the tank while sucking in air so it looses prime when truck sits.

 

What lift pump do you have? Do you have a fuel pressure gauge installed?

Edited November 5, 2017 by JAG1

[FWBDieselJay]

Pressurized the tank this morning and didn't see or hear any signs of leakage. 

 

Am I to assume I'm looking at a bad injection pump?

 

[Mopar1973Man]

13 minutes ago, FWBDieselJay said:

Pressurized the tank this morning and didn't see or hear any signs of leakage. 

 

Am I to assume I'm looking at a bad injection pump?

 

 

Very possible... I would do the BlueChip hot wire trick on the VP44 to verify the pump is truly dead. This removes the ECM and all computer and the VP44 is hot wired to run solo it should start and idle that's all if the pump is good. If the VP44 failed it will not start.

 

Being there is no other error codes I would also have the alternator tested being it very possible the alternator had failed and was feeding way too much AC noise and killed the PSG on the VP44.

[JAG1]

Don't give up cracking three injectors too while trying to start.

[FWBDieselJay]

Well, I broke down and replaced the injection pump and bled the fuel lines after. She fired right up.  

 

I drove it for about 60 miles or so, and it died again.  

 

I'm at a loss.  It ran strong and have me only a slight "dead pedal" feel until it fell on its face.  

 

Planning on bleeding the lines again this week to see if it's somehow just losing its prime.

 

Any other ideas?

[notlimah]

Low or no voltage to the lift pump? Bad lift pump? What’s your fuel pressure? 

[FWBDieselJay]

Lift pump is putting out 15 PSI. First thing I checked.  

[notlimah]

Is that changing when your having the issue? 

[kzimmer]

Aaaaaaaaaair

[FWBDieselJay]

I suppose that's a good question. I guess I can't really say, because the motor shuts down so quick...

 

I pressurized the tank and didn't hear any leaks.  We are going to tear into it on Tuesday. 

[FWBDieselJay]

Ok guys, I'm completely stumped.  I changed the injection pump.  Bled the lines and it fired up. I drove it 60 miles and it died again. 

 

Pensacola Fuel Injection replaced the pump, and I reinstalled another brand new pump. Bled the lines, and it wont start.  

 

Crank position sensor has been replaced, and APPS, has been replaced too. The lift pump is working.  I can hear it, it fills the filter bowl, and after putting a gauge on it, I've got 15 PSI.  

 

WTF?!?!?

[Mopar1973Man]

Any security function on the truck? 

 

Wait to Start light coming on instantly with the key or not? 

 

Any error codes present?