Yesterday my wife and I were out running errands, heading home on the highway when the truck began to sputter, blow blue smoke, and then completely died.  We got towed home and how I'm starting to diagnose the issue. 

 

Background - About 700 miles ago the truck was throwing a P2016 code.  I installed a filter / new lift pump from NAPA,  and a new VP44 from Pacific Fuel Injection in Portland.  I also replaced the crank position sensor while I was there.  The installation went well, and the truck drove with renewed strength; even towing a 10k RV trailer for over 350 miles. 

 

Here is what I know now:

1. There are no engine codes throwing
2. The VP44 keyway is still in position (see picture below; the angle was hard to shoot with my camera)
3. The lift pump pressure is ~13PSI
4. When I crank with the injector seats slightly loosened, I see fuel pooling underneath

 

I began the process of pulling the pump believing that I receieved a bad unit.  All injection lines are off the truck and I'm ready to pull the pump out.  As you can see in the photo below, I was test-threading some puller bolts in preparation of removing the pump and attempting a re-seat.  After getting a better look at the keyway, it is apparent that the key is indeed seated.  So now I'm at a stopping point - Any assistance is appreciated. 

 

Thanks from Washington,

Ty

Sounds like maybe that lift pump is no good. If it's just a stock replacement, those are junk. Honestly surprised to hear you're even getting 13psi. Where is that measured from?

 

Also one of the mods should move this to the 2nd gen power train section, you accidentally posted in the 3rd gen section.

Moved to 2nd gen section

oem lift pumps are junk. toss it and get a strong lift pump. I recommend a fuel boss mechanical, others will recommend an electrical. Up to you.  both are gonna be around the same price. I like the fuel boss as it is not prone to failure from all the electrical stuff on the other pumps. plus it increases fuel flow and psi when rpm goes up. it is simple and reliable. But most of all dont run that replacement VP44 without a good lift pump, eventually its life will come to a short end as the first one did.

my fuel boss runs around 18-20 psi idle and normal driving goes up to ~24psi. when i hammer down i cant get it below 18-20psi. you need something that will sustain over 14psi to keep fuel flowing through vp44 to ensure proper cooling.

Thanks for the feedback on the lift pump.  Are you saying that my lift pump is proximate cause for my situation right now?  I want to focus on getting it operational; I'm not opposed to swapping it out once I know what it will take to get the thing running. 

I think it's possible the lift pump caused your problem but with no codes it's hard to say. The previous code you had would've had me doing the same thing as you in checking the VP first, but if it's still aligned then seems good to me. I'd double check all connectors to make sure they're all snug and no bare wires are causing a short anywhere. 

 

For the truck to randomly sputter and die and not throw a code seems weird. I mean I know a VP can die and not throw a code but since yours is new it's hard to call that the culprit. 

 

Worse case scenario is you warrantee the VP. Best case is after checking things over again you start her up and she runs fine, then get a new lift pump in ASAP! 

Edited June 6, 20168 yr by notlimah

How are you measuring your fuel pressure?  Do you have a gauge in the cap that you can monitor the pressure at idle and WOT?  Some IP rebuilder will not warrantee a VP44 if you are using the stock pump...take that for what it is worth.  Also, go through and make sure all of your electrical connections are tight.  There was a guy on here a week or so ago that at stuttering issues and it turns out his battery connections were loose. 

It would be a good idea to make sure that  your filter is good and not plugged and that your fuel is good, no water. 

I would guess you got a bad vp44 if it ran then stopped so shortly after replacing.  

random thought, have you checked the return line check valve to make sure its closing properly? they open at 14psi but can stick open on worn ones causing no pressure at pump, especially with oem lift pump

@CUMMINSDIESELPWR - how do I check the check valve?  Was that the part which came with the new pump?

 

@Me78569 - is there a way to diagnose that before contacting the supplier?  

 

@Hawkez - I'll check the electrical connections and may add dilectric grease to the plug.  Also, the lift pump was a different design from the OEM.  The guy at NAPA said that the originals were crap and that this design was the same one used by most of the aftermarket suppliers.  Here is a link: http://www.napaonline.com/napa/en/p/AFPE7153/AFPE7153_0397462450

 

Where I left things yesterdaythis I am ready to put a puller on the pump. Based on the recommendations in this thread, I may want to reassemble the machine and verify other components.  At this point I am not sure if I should be relieved or disappointed that the keyway had not slipped. At least that would be proximate cause.

 

Thanks everyone for your support!

Its a little difficult if there are no codes to point to he vp.

 

I would say you should work through all other things and rule out other things before moving to the VP44, but typically the last part you replaced is the one that is to blame when something happens.

 

Verify all plugs are clean and seated well, verify that you get good fuel to the vp44 and fuel from the lines when cranking, 

 

Verify the overflow is working as expected ( we have an article for that)

 

Check and tighten  / clean all power and ground connections to the bat and block.

Your pump should have came with a new overflow valve.  You can do a hot wire test on your VP44, it is really easy, but since you have disconnected your fuel lines it may complicate things.    http://www.bluechipdiesel.com/vp44_diagnostics.html  This test takes everything but the VP44 out of the equation. 

 

I'd be surprised if that lift pump from napa provided adequate pressure, I'm sure the guy behind the counter told you his was good enough, but I doubt that.  I run a mechanical pump and my pressures, as I can read them from the cab, are constant. 

to test the overflow valve, take it off and simply try to blow into it. if you cant push air past the check ball then it is seating. to test if its functioning properly hook a compressor tip to the end and see if it opens up past 14psi. if it opens sooner its faulty.

 

its just a steel ball spring loaded to keep backflow from happening and draining the system

An update and thanks...

 

I reassembled the fuel system last night.  Along the way I verified the return valve worked.  Then the fuel filter, and it was clean.  I swapped out the fuel relay with the spare..  So far all components working.

 

Before hot jumping the VP44, I wanted to bleed the lines.  I got fuel to 6, then 1, then 5, then 2.  3 & 4 would not bleed.  I loosened them even more and watched as my son cranked for 10 second intervals.  As I saw fuel and green bubbles emerge from the remaining lines, the truck grunted!  After securing the remainder, the truck started with little trouble.  

 

My my working hypothesis is that low fuel caused this condition.  I was at 1/8 of a tank that day, and had to hard-accelerate on to a highway from an unlevel approach road.  Between idling waiting for an opening and the hard thrust on to the highway I must have created a large air gap in the lines.  The stall occurred 5 miles later.

 

As a side note, I looked at a new lift pump from FASS.  The unit was exactly the same size and shape as my NAPA unit.  Apparently the OEM Carter pumps are such crap, NAPA sells an Airtex/Delphi pump as the stock replacement.  Looks to be from the same factory as the FASS. I tested my PSI while driving (not easy to do with the gauge sticking through the hood) and it read 16 psi under load.  I'll hookup an interior gauge, but for now I'm sticking with it.  

 

I appreciate the assistance & effort from this community.  

Thanks

Ty

 

 

Good to hear, hopefully you have no problems in the future.

glad it worked out.  

 

i try to carry a wrench to bleed injectors as ive got air in the lines from snapping the throttle shut with my TST dialed up.  i had plenty of fuel.  

I have that same Airtex pump on my truck but only use it as a backup and have it disconnected since I have a Fuel Boss pump.  When I have run only the Airtex pump I'm getting 15-16psi at idle and 11-12psi at WOT, so not a very good main lift pump. 

 

I just got called out yesterday morning at 7am for truck that died alone the highway. Come to find out the truck has problem or issues pulling fuel the tank. The fuel gauge is correct but is running out of fuel at around 3/8 to 1/2 tank of fuel. So watch this time around for when it at up based on level. Yeah the owner fill thee tank and it only took 20 gallons so the gauge was correct but the factory pickup is got an issue.