Friends truck stumbles and dies

[That Guy]

I feel special today for having a reason to post in the 24V section, but I digress.

 

Friend bought a 01 2500 2wd auto and it has about 310k on it. The injection pump and injectors had been replaced just before they bought it. $3000 and had a "bottom end knock" which turned out to be a cracked flex plate. 

 

So, the fuel pump went out on him and he replaced the in tank unit and the block mounted pump. Ran fine for several days and then it stutters and dies. He bleeds up to the injection pump and it fires off. Makes it about 3 blocks and does the same. Won't fire back up. (He is one of the duller knifes in the drawer but learns his lesson. Hard to get all the information out of him because he doesn't associate things.)

 

Calls me, I show up tools in hand. Getting plenty of fuel to the injection pump. Was only coming out on the No 4 injector line. Wasn't getting a drop from 1-3-5. Couldn't get to No 2 and didn't try 6. Electrical checked out so I moved onto fuel, took forever to bleed so I gave up. Disconnected the grid heater and shot some ether into the turbo with the lines cracked. 10 seconds in, fuel is pouring out of the lines so I tighten them up and it idles. Has the odd stumble. Shut it down after a few minutes. Won't fire on its own. Fire it up on ether again and he fills the tank. The stumble stopped once some fuel was in it again. 

 

 

Now, I suspect he may have gotten the supply and return lines crossed when he installed the new sender/pickup assy, or maybe the new sender is bad and sucking air at 3/8ths of a tank. Am I wrong in my assumption? Other ideas? My first time turning wrenches on a VP44 truck. He did make it 20 miles back home without incident. 

Edited January 14, 2021 by That Guy

[JAG1]

fuel module screens clogged or sucking thru old in tank lift pump? Watch that inlet screen sometimes placed inside the inlet side of the aftermarket Raptors. Don't know about other brands, but tends to get clogged. I just pulled mine out with needle pliers. since I have pre filters.

[That Guy]

Replaced whole in tank unit. No pump was in the tank, still had the old unit sitting in the bed, just the 2 wires going to the fuel level sender. I checked it out and am not sure why he replaced it. Has factory style electric pump mounted under the factory fuel filter assembly. 

 

I'll check the screen next time I see him, hopefully not on the side of the road again.

[Mopar1973Man]

One to look for is a cracked pickup tube. I've seen 2 different truck now that fail after about 1/4 to 1/2 tank. The corrugated tube for the pick up could crack all one corrugated tube and its hard to spot. 

[Dieselfuture]

Sounds like it's sucking air, once tank had more fuel no problems. 

[NIsaacs]

What did he replace the module with, oem or aftermarket, such as Vulcan?

 

There are slots in the outer sleeve with screws threaded in the inner portion. I think it is shipped with the two pieces collapsed and the screws tight. Maybe he installed it that way and now it does not reach the bottom of the tank??

 

The Vulcan does not have the screws, it is an open design.

 

  

[That Guy]

4 hours ago, Mopar1973Man said:

One to look for is a cracked pickup tube. I've seen 2 different truck now that fail after about 1/4 to 1/2 tank. The corrugated tube for the pick up could crack all one corrugated tube and its hard to spot. 

 

4 hours ago, NIsaacs said:

What did he replace the module with, oem or aftermarket, such as Vulcan?

 

There are slots in the outer sleeve with screws threaded in the inner portion. I think it is shipped with the two pieces collapsed and the screws tight. Maybe he installed it that way and now it does not reach the bottom of the tank??

 

The Vulcan does not have the screws, it is an open design.

 

  

The pickup was some auto store unit. He said it was more open on the sides than the factory one. I also suspect it has the corrugated tube may be cracked. 

 

If I think through the whole thing in my head, he probably got it back bled and running and then drove up/down a hill and caused it to pull more air that it wasn't pulling.

 

At this point, I've convinced him to check the in tank unit. My personal preference is to pick up the side of the bed and his is to drop the tank. Said he wants to wait until the ground isn't frozen.

 

Edited January 14, 2021 by That Guy