Lift pump
Originally posted by Tomscreek
I didn't read through all the posts here but I thought I recently read in one of the TDR publications an article about the lift pumps and how even if the lift pump fails entirely, the engine will run fine without it. ?????
Here's a good one:
About 8 months ago I went to pull (via the fuel filter drain and long clear hose) some fuel from my wifes 1999 2500 2wd auto to use for cleaning something. It wouldn't drain when I opened the valve so I turned on the key and you could hear the pump running, still no fuel. closed it, started the truck, cracked it, no fuel, opened it all the way, no fuel. I figured the valve bad and would look at it next filter change. Went to my truck (2001 2500 4wd 6 spd) with the clear line and had all the fuel I needed in my coffee can just by turning the key on.
Last month 09/03/03, fuel filters for both, popped the cover on mine, drained/ pulled filter, cleaned bowl w/lint free rags, new filter, put cap on loose, cycled key twice filling the filter, torqued the cover, truck starts runs fine.
Wifes, whole different story, drain still wouldn't drain until filter loose then drained fine. new filter in, cycled ignition w/outlet line loose, pump runs but no fuel, after about 30 times, pulling the filter inlet line and airing (2-3 psi) the tank to see if fuel would flow, I knew I had a bad lift pump. This is still under warranty... ... Riiiiiiiiiiiiiiight, so I leave it as is. I leave on detachment in two days so I have my wife call dealer to come get, and tell them what "is" wrong and the process which led to it, they treated her like they were talking to a woman on the phone who's counterpart got into something over his head, but they flat bedded it away.
So I show to pick it up at 17:59 "done" the same day to be told that the only thing they had to do was to bleed the fuel rail (fuel rail?) and that every thing else was fine. When I asked about the lift pump, they assured me that that checked out good also. So I got nailed with a 129. 47 bill for tow and fix. I'm less than thrilled but I don't make a scene. I know it's still bad but it still starts and runs now.
Sooo, I order 2 pressure gauge sets from Geno's, one for mine one for her's. Installed on mine last week after returning from detachment (prototype installs always first on my truck, because my wife doesn't want me breaking her's w/ "improvements"), did her's yesterday, when I removed the bolt at the injection pump for the install of the sending unit, no fuel leaked, cycled the key, pump ran but still no fuel. Installed the gauge completely, again had air in the lines w/o lift pump, no start etc, and a guage that was bad or actually was indicating what kind of pressure I had, zero psi.
I pulled the book, did the injector bleed procedure, truck fires right up, gauge reads a needle below zero (vacuum?). Today (saturday)I took to dealer, service dept closes in two minutes, everbody gone, gotta be monday. So now I wait til monday.
Bottom line: this truck has been running a long time w/o a lift pump operating properly and running fairly well, but it hasn't been loaded (grocery getter/commuter). What damage is done? who knows, but nothing good has come of it, that much I do know.
It makes more noise than mine, smokes a little on startup and doesn't get as good gas mileage as mine. Now I think I know what might be the root of that.
My wife noted the difference while using mine, while I was doing shocks/fuel pressure gauge. I had just noticed the noise.
Gotta wait til monday to see if it checks "good" again.
Still do not get fuel when I open the water drain, it sucks in.
I'm going to point the hose at somebody at the dealer when I demonstrate monday, believe me there will be no harm done.
Oh yea, gauge on my truck reads 12/13 @ idle/cruise and never goes below 8/9 under other conditions. Good lift pump? At least it's working.