Engine/Transmission (1998.5 - 2002) lift pump

[pokeytwins]

AD sent me a new pump and immediately it was putting out 23 PSI. That next day the diesel shop told me the VP was throwing out bad codes and while i was driving it, it totally quit. So VP probably was the cause of the “surging” which was happening before the AirDog replacement.

I had a rebulit VP from Boasch installed ($1,600). After this the truck is running great showing 18/20 PSI, no surging for about 50/75 miles around town, 15 minute or so trips.

I took truck on its first long, 300 mile round trip drive with the nre VO and AD. PSI stated to drop about 40 miles into the trip. At the 150 mile destination, PSI was 12/14. I filled tank and added 1 oz 2 cycle ash less oil per gallon of fuel (which I have done since I bought the truck). By the time I got home PSI at 10/12 and at acceleration 8. Next morning PSI at 14/16 and about 10 minutes into the drive it jumped up to 19/20. Stayed there for about 10 minutes and at the end of the 30 mile drive it was at 10/12, 6 under accleration.
Now parked near my diesel shop and again I need advice????????????????????????

Choices:
try and get another new AD lift pump. (free)
Replace with a Fass
Replace with a Mechanical Lift pump
Sell the truck (wife will be extremely happy)

Thanks Russell

 

[SnoKing]

Air leak on the suction side of the pump? Stuff in tank getting on the pickup screen? Bad AD? Faulty fuel press gauge? Return line check value issue(was a new one installed with the new VP-44?)? SNOKING

 

[Crazy Horse]

Not trying to be a problem here but... From what I remember from when I put my Walbro on in place of the factory transfer pump, 17-18 psi was the max recommended fuel pressure to the VP. The Walbro has been putting out (at the VP inlet) 14-16 psi religiously since installed in 2009. The only time it's at the lower end id when hot weather is here and the fuel is thinner in the summer, acceleration, idle, or cruising. That's not an a reading from an electric gauge either, it's plumbed with a protected fuel line into a liquid filled gauge in the cab.
Phil

 

[pokeytwins]

before but only used about 5 miles and vp quit. but truck was surging and the new vp cured that.

 

[DTWeber]

you could have a bad pressure relief valve ,not everything made in US anymore

 

[SnoKing]

before but only used about 5 miles and vp quit. but truck was surging and the new vp cured that.

So do you still have the old pressure relief valve to try? SNOKING

 

[pokeytwins]

unfortunately I do not wrench, I'm having the shop check valve.

Thoughts on FueLab lift pump?

 

[bry1216]

Just wondering if you ever solved this issue?

 

[pokeytwins]

Just wondering if you ever solved this issue?

Yes, finally a shop in Jacksonville NC found a "ground" problem. Has been running at 20psi. I don't drive it much, about 500 miles