Need help! Need the truck this week.

I'll put a megger on both of those power feeds and see what kind of resistance I get thru the wiring.
Thanks.

 

Makes me wonder if that connector needs repaired or replaced.
Definitely a place to look. It is a 24 year old truck and if it's original......

 

Sorry for the delay but life got in the way.
I got the new fuel pump in and went to go put it on and I think I found what MIGHT be causing my issues. It is something that needs fixed but not sure it would 100% cause my issue. Putting it back together will be the only way to verify,,,

When the old fuel pump was pulled off, I found the plastic coupler between the drive gear and the pump gear was completely gone! The pump was running gear-on-gear allowing a lot of play between the 2 gears.

My mind is telling me that when I was letting off the throttle (sudden change in engine speed) would then give a brief lapse of fuel pressure in the fuel rail and then shut the engine down for fuel rail pressure.
Problem with this theory is there has never been a low FRP code set.
Maybe it was fast enough to shut the truck down but not long enough to set a code???

But, yet another issue found and getting fixed with the old girl which is a major plus.

 

I don't know if anyone is following this thread anymore, but I have an update.
Got the new fuel pump in. Took a trip to the local Hydraulic shop (150 miles away) and finished the install.
Bled the system and she started right up. I did notice she had a "smoother" sounding idle than before but I just shrugged it off and thought I was being optimistic.
Let her idle for about an hour while I did my morning chores.
Look her out for a 2 hour drive and she did not shut down once!

Thanks for all the great ideas and replies guys!

 

I hope the headaches this thing has given me and a solution will help someone in the future.

I am going to look at that power supply also. I haven't read it yet but the fuel pump wouldn't cause them codes.

Right now, I'm just happy its running without dying. Time to haul some things!