Engine/Transmission (1998.5 - 2002) could this be a VP-44 or some thing other

[grass hopper]

it all started back in July when i took my brother & our son's fishing at the coast i was pulling my bass boat we stopped to get fuel when i was there i was looking around and found a fuel additive for diesel so i got it put it in the truck ran fine all the way there (about 350 mile one way) on the way back i stopped to fill up and got some more of that magic juice add it to the tank and took off i get about 75 mile from the house and the truck acted like it ran out of fuel for just a second then it was fine but then it did it again & again for about 10 mile. Got home checked it out it was fine never did it again until about three weeks ago that’s when my '99 3500 acted like it ran out of fuel for just a second then came back to life. The next day it did it two times back to back. That’s when i went out and got me a scanner. i pulled a injector pump code (p6100 if i remember right) i went ahead & replaced the lift pump and the filter cleared the code and drove about 50 miles with out the truck doing any thing bad. Just as i got into my town it started to act like it was running out of fuel again. When i got home i checked it to see if i tripped any codes. Sure enough that code i had erased came back. well i have been driving my truck for two weeks just to work and back about 20 mile round trip not going over 55mph & not having the truck try and defuel on me. Well last Thursday i fingered i would check for a code it was there. i removed it and then drove about 85 mile round trip on the highway i would take it up to 80mph at times then i would take it down to 45mph in 5th gear and stand on it (put a heavy load on her) the truck worked fine. got home checked for any codes none, passed, O. K. i have checked it two other times this weekend just to make sure and it keep telling me passed. Could this just of been a gremlins or should i go ahead and replace my VP-44?

 

[Gary - K7GLD]

I don't find any "P6100" codes listed for your truck - need more info.



What fuel pressure are you seeing?



You *DO HAVE* a fuel PSI guage, RIGHT?



Sometimes, even NEW LP's are weak or poor outta the box - or a bad connector will STILL make a bad connection on the new pump!



GUAGES, GUAGES, GUAGES...



They are the FIRST line of defense, otherwise, we are all left with long distance guesswork and flying blind!



SO, without knowing IF, or WHAT fuel PSI you have, we are left with a few possibilities that USUALLY apply in cases like yours...



Plugged in-tank filter

plugged fuel line

kinked fuel line

air leak in fuel line

clogged fuel filter

weak/intermittant lift pump

Bad/poor LP plug connection

bad/poor VP-44 electrical connection

bad/corroded ECM connection

bad/poor PCM connection

failing ignition switch

clogged LP internal filter

leaking LP pump plate

bad fuel

bad APPS/TPS

bad LP

Bad VP-44

bad CPS

There's just a few possibilities - a fuel PSI guage would eliminate about 2/3 of them - and other members will have additional suggestions...



Good luck.