Lift pump and P0628

[nickleinonen]

... it's alive again. .

what a pain in the rear this was though. there is so little room to do the plumbing nicely so i kinda mickey moused it as i needed to get my truck running again. so outside the frame rail the pump, relief valve and prefilter went. i need to tear it all apart again when the nice weather comes back so i can properly plumb it and get a gauge in the cab to monitor it. with the engine not running, i have about 18psi on a test gauge

 

[MickeyMiller]

I've got 95K miles on the original lift pump. What code should I expect to see if the original pump dies?

 

[nickleinonen]

I've got 95K miles on the original lift pump. What code should I expect to see if the original pump dies?

you will have an engine that won't start/run with a dead lift pump. . i didn't get a check engine light, but i did get a code when i checked it. .



i did notice while i was doing a lot of driving today, that my truck has more pep. . before lift pump died, i was making about 27psi boost under load. today i was making just over 30psi boost with no other changes other than the walbro under the truck. . i guess i was starving the cp3 for fuel before the pump croaked. .



truck is gonna get big lines [-8] from stock filter to cp3 come spring through a 2µ filter. i think i need to swing by the local pete dealer though. . they have a good deal on the cat 1r0749 filters for $14. 99...

 

[MickeyMiller]

One month later and I got to answer my own question... it threw the P628 code when the lift pump failed. Per Richard at Glacier (I ordered his Walbro kit this morning) this code usually indicates a worn spot on the stock lift pumps armature. If I let it cool, it will fire up... then dies after about 5 minutes.



BTW, it also threw thw P837 "Four Wheel Drive Switch Performance/Rationality"... I have the manual lever transfer case, any idea how/why/what with the P837?

 

[nickleinonen]

for the 4x4 switch thing, does the 4x4 light come up on the dash when you put it in 4x4? if not, maybe a bad switch or bad wiring. . if it all seems to be working, ignore it [p837]

 

[MickeyMiller]

Just went out and checked, 4X4 lights up in both 4HI and 4LO. I am planning on changing the T-case fluid this week anyway, so I will pull and clean the selector switch connector and see if that does it.



Thanks for the input!