Inj pump life expectancy after Lift Pump Failure

[thechevyhdman]

Well...solved my cold stall problem...Lift pump failure. Yesterday I started my truck and it would not run for more than 1 minute until completely warmed up. Today same deal, I parked it (didnt wanna kill my starter)...Replaced lift pump and all is well. Now Im kinda not smart on 6.5s. That must of meant my inj pump was "sucking fuel" on its own with no help from the lift pump....Do you think my lift pump crapped out on monday when it first started stalling, Or has this been going downhill on me for a long time....Im just kinda getting at how much more time does my Inj. pump have left
I still have 4 years and 30k left of warranty on Inj pump...Just dont want it going downhill snowplowing this winter
Bill

[charliepeterson]

The summer heat and an inadequate supply of fuel to help cool and lube the Injection Pump is what kills it. It will tell you when it's dieing. Watch for the SES. These pumps don't die over night.

[charliepeterson]

The summer heat and an inadequate supply of fuel to help cool and lube the Injection Pump is what kills it. It will tell you when it's dieing. Watch for the SES. These pumps don't die over night.

[thechevyhdman]

This SOB truck...Stalling again. I carried a spare fuel filter as I thought maybe lift pump going south might have caused a metal shaving restriction...Now my guess is going to a) an air leak....As changing lift pump no further problems...for 8 hrs....then I change fuel filter....no further problems for the 2.5 hrs I used it for work tonight. I think I might have goofed....My truck has dual tanks.. I think that theirs another pump under the cab of the truck..the one I replaced was between the two tanks...(balance pump) I doubt thats the case I dunno...I need some suggestions...
Truck is 1998 Cab and Chassis,dual tanks,92,000 hard miles..Had this problem before. I think the balance pump crapped out...truck only drew gas from one tank...causing something else to crap out....I need ideas.
TIA Bill

[rjwest]

Assuming a 6.5 electronic injector pump.
Most likely FSD, they are temp sensitive...
and can cause stalling after starts like a " fuel starvation.

Check Fuel pressure Listen for Lift pump
when key turned on....

Also feel Fuel solenoid when someone turns ign on/off
, should feel solenoid open/close...

If 96 and later, there is a connector under hood
in cable by hood hinge , left side,
jumper to 12V to run lift pump, open water drain
to check fuel flow....

[GARY PAGE]

Attach a pressure instrument on the drain line a check 4PSI min.

[ucdavis]

I'm guessing that failure to supply adequate fuel (i.e. lubrication) to IP parts that are expected to produce 1700 psi injection pressure will start to wear on the IP.
How much wear and how much lifespan lost will depend on the extent of stress on the parts. My first IP had the steel rollers & died @ 25K miles. I just happened to rewire the lift pump direct to (switched) 12V cuz I couldn't find 12V @ the LP under any condition (I was priming the new pump), but when I undid the mod, the LP still wasn't working. I'm now thinking my OPS (which was the culprit) crapped out about 20K or so, and the rest of the miles killed the IP.

[thechevyhdman]

Lift pump is making pressure, with key turned on, (but not running) she pumps out fuel fine...and I can hear it tick when it is running. I used the line on the front of engine that connects to the bottom of filter housing...Its a cold stall, I dont think it is PMD related, I think its air in fuel related, Or a problem between the Inj pump and injectors, But I havent had the time to crack and injector to see if its getting fuel.
Most PMD probs Ive had were on our earlier 6.5's...and only happened when warm.
I tried looking for the lift pump wiring so I could jump it to see if its working, But their are two flat connectors under the master cylinder..and the lowest part of the firewall.Ill just bring a big jumper down to the pump itself....I assume white (pos) and brown (neg)
When it stalls it usually goes like this. I start her up, runs fine cranks right over. I run down the street she stalls.....Sometimes it cranks right over and sometimes it just cranks and cranks....I can sometimes keep it running by revving the heck out of it....It really just seems like an air prob, but I cannot find any leaks...Oh and yeah I did mistakingly replace the balance pump rather that theLP.
Is their any off and on failure with LP's....They dont seem like a pump to work and not....minus grounding issues...seems like once it goes its done.
Any other ideas/ recommendations
What are symptons of inj. pump failures
Bill

[ucdavis]

Your symptoms could spell IP failure, but if you are not getting any codes it is best to look at everything else to assure that a cheap part or circuit fix isn't the trouble.
Stumbling, stalling or missing can spring a code 35 or 36 or nothing, and come from the fuel solenoid on IP. Codes 17 or 18 don't come with symptoms that I know of, but are associated w/the optical sensor failing (black gizmo on top of IP. (for OBD2 those would be 1216, 1217, 0215 & 0370 respectively.)
SES light comes w/these codes, along w/"backup fuel" curve or "limp mode" (if code conditions are severe) in which you have loss of power due to an unvarying fuel curve vs. actal driving circumstances.

[rjwest]

My truck would start than die like fuel starvation.
did so for several days, than one day ran fine,
next day same problem
IT WAS THS FSD, At the right temp it would fail.
Colder OK, warmer ok....

Remote FSD fixed it.

Several weeks later I reconnected the " suspect bad FSD" ran for a couple weeks, than same problem....
Swapped back to remote FSD, Started up ran fine..

I had no code, through all of this...

[thechevyhdman]

Whoa if this post is up twice I am sorry computer issue. I have no codes, at least no"hard" ses light codes. Its weird Ive been having this cold stall for almost 3 months now...It would only happen if I started up my truck and pretty much took right off down the road...I been letting her warm up lately and no probs...I dunno..Im starting to hate this truck anyways...would of replaced it a year ago, but no good belt driven PTO options on the Duramax.
Bill

[moondoggie]

Good Day!

I never guess about lift pump function, I test. On my trucks it's easy. I hook up a pressure gauge to the vent port on the top of the fuel filter, crack the port open, then do two tests. 1) Put tranny in anything except park or neutral & turn key to crank. Engine won't crank, but lift pump will run. 2) Put truck in part & start. I see 4 PSI or so either way.

This might not work on your truck. Maybe the 1st test doesn't work for your year. Someone said somewhere else that the newer trucks like yours, the 'puter runs the lift pump after the engine starts, & maybe it's not always on when running anymore.

I wish you luck. I put this here because for 95 & earlier, it's silly to guess about lift pump function by listening for sounds, or checking for power at the lift pump. All functions can be checked with a pressure gauge & hose, without getting dirty even.

Blessings!

Brian Johnson, #5044

[ 11-28-2003, 01:34 PM: Message edited by: moondoggie ]

[charliepeterson]

Bill:

With the truck running, go to the front beside the thermostat housing and find the small "T" valve with a black hose stuffed down the front of the engine. Pull the hose up and point it into a can. This is the water drain circut out of the fuel filter housing. You should see a good supply of fuel coming out of this hose (pencil tip spray).
If nothing really comes out you confirmed the lift pump circut with the truck running is dead. You already confirmed that the circut is good while cranking.
If this is true then you now go to the oil pressure switch located below and behind the fuel filter housing.
The lift pump is controlled from two differant circuts going back to the ECM controlled by a relay in the under hood fuse box center.
This relay seems to be very reliable but the oil pressure switch is a known problem.

Your problem does seem like a fuel delivery issue.

[tom.mcinerney]

If you have any will/time remaining after the OPS renewal you might consider pulling the fuel filter/conditioner assembly. The oring at the fuel heater(unscrew plastic ring-nut at base assembly)seems to dry out and leak eventually. The hoses are fine quality, clamps maybe little loose.

[thechevyhdman]

I undid the T valve, and got a good spray of diesel....on second ideas what does the Oil Pressure Switch look like .....Im ****ed I tryed doing a CV joint tonight for the first time....GD MF'n POS rebuilt USA Cv joint pos.......my front end is in pieces i wanna set this truck on fire
Bill