Need help! Need the truck this week.

Replaced the harness to the TPS. No change what's so ever.

Wonder if I'm losing enough FRP on decel to kill the engine but not throw a code?

 

A definite point to go look at and will do.
I'm thinking that this circuit (one of the 2 from the battery) may have an issue or it's throwing this code when I go to start it after it dies going down the road due to the fluctuation of the power while it's supposed to be steady while driving.
The batteries are new and load tested them just 2 months ago, but never hurts to check them again.
But it still doesn't explain why it only happens when the throttle is let off of. A problem with the power supply wiring would be more random than just happening at specific points I would think.

And please don't take it personally that I am questioning everything. I'm just trying to figure this thing out.
Perfect example is....
I was at Cummins yesterday with the truck and talking to a tech.
He says, "Sounds like a fuel pump going bad."
I say, "But wouldn't that throw a code for low fuel rail pressure if it wasn't getting any fuel?"
Ha says "Yes it would."

 

So, with the history I've had with this truck and the fuel system, I have decided to just throw a fuel pump at it and see what it does. The pump and delivery hose will be here this next week and I'll go from there.

The Cummins tech did say it sounds like a fuel pump issue so I am going to get that done and go from there.

While I am waiting for those to come in, I will be checking those power leads from the batteries.

Once it's in, I have a 250 mile trip planned withit to see how she does.

 

The last 6 of my VIN are A76578 and my Engine serial number is 11901820.
It looks like I will need to find the wiring schematic to test the connections and wires at the ECM ro see which ones can be give power to and which ones cant be.
I have a Megger an I can test the insulation factors of each wire also to see if anything is grounded or close to breaking thru the insulation.
As far as my scan tool, I have this one. Since the truck is for personal use, I cant justify a $10k laptop for diagnostic purposes.
Diesel Laptops Handheld Heavy-Duty Scan Tool with Regen

But, I mention the "history" of the fuel issues with this truck and mentioned some of the parts I've put into it and I'll share that now so everyone knows.

I bought the truck last year and took it on the my first trip. Changed all the fluids and filters before my maiden voyage with the truck
Climbing over Eisenhower pass headed towards Denver, suddenly the truck had a hard time staying running.
Limped it into Denver for the night and would look into it in the morning.
Found the driver's side tank has a bad pick up tube inside and at a half tank, she starts sucking air into the fuel system.
Also noticed the fuel lines are in terrible condition SO, I replace the hoses between the tanks and fix that situation with a little re-arranging.
Next morning, I'm back on the road. Goes good for about 250 miles and it starts to act up again.
Pull into a shop and have the codes read. (Didn't have the reader yet and that code read cost $200)
Had codes for all 6 injectors and the 5 volt power supply. Also had a few indications that something was going on with the fuel system.
This is where I found out about the cooling plate and check valve behind the ECM.
Pulled it off and it was FULL of rubber hose linings.
So there I was flushing and back flushing the cooling plate and the fuel system.
Get the system all back together and back on the road.
Found out then that the low fuel flow damage has been done.
Ordered and replaced all 6 injectors across the road from Fleet Pride. BTW, I just love how easy Cummins made this engine to work on. haha
Get back on the road and I think this is where the current condition started but not exactly sure, but I then start thinking about the ECM getting cooled by the fuel and wondering if damage was done by over heat due to the lack of fuel flow thru the cooler.
Got it home (limping it with this shut down issue) and that is when I get the code reader and decide to have the ECM rebuilt.
Was informed that the injector driver was burnt and that would be causing the faults I was getting.
Got the ECM back and the injector codes and 5 volt supply fault are gone. Haven't come back.
Still having the shut down issue though.

I don't think I really need to go into the other issues I had with the truck on this trip, but let's just say that a 8 day trip ended up being a 2.5 week ordeal and even had to get towed once, but that was not fuel related.

But, it has me questioning whether this is still a cascade effect of that expensive and hair pulling trip with the fuel system?
Maybe a piece of hose got into the fuel pump.....past both filters???
Maybe the lack of fuel caused a check valve to malfunction and pressure inside the pump is back feeding and causing shutdown on Deceleration?
I'm not sure but the new pump will be here on Monday.
I'll see what it does and also be looking for a schematic to do the electrical testing/diagnosing.

Keep the ideas coming guys. I really appreciate them!
As of right now, I have been volunteered with the truck to help by Brother-in-law to move from Oak Harbor, WA to Colbran, CO in about a month.
Really don't want to have another disastrous trip with the truck like my first one was.

 

Thanks.
I just had this ECM rebuilt and tested. Talked to them and they say to send it back to them to get tested and verified without defects.
I'm just not sure it's the ECM.
I'll go register now and see what it has to say.