How to Replace 01 Cummins Fuel Return check valve VP44

Still chasing down my hard start issue after sitting. This also wasn't my issue but its another common one checked off the list of things. Hopefully I'll get this sorted out sooner than later. I hope you enjoyed the video.
Instagram @AllThingsBoost

[@AllThingsBoost]

Final fix: fuel was leaking at the head. I replaced the VP44 hard lines, didnt stop leaking. I replaced the injector crossover tubes and it stopped leaking and it starts like it should now. I probably should have started with the crossover tubes, but between them and the lines things are good to go. Go check out more recent videos on those installs.

[@Mr.Atwood]

Injector crossover tubes? Are you talking about the brass lines or what

[@AllThingsBoost]

@@Mr.Atwood Google them and you'll see what they are. I also have another video replacing them on the channel.

[@justsaynrush9689]

I had truck issues and they did an excessive return test and said the crossover tubes where leaking. When I took them out none were loose and I couldn't see anything That I could see to make me believe that was the problem. Did you see an obvious problem with yours. My truck is a 2005. Could I have the same check valve?

[@AllThingsBoost]

@@justsaynrush9689 other than the fuel leak at the head being visible, looking at the tubes themselves I saw no visual issues.

[@MsDonGoofy]

One info if your car start hard over night: That bosch overflow valve it have a blender for air bubbles bulit in, (that small hol) and it won't keep the pressure into the fuel pump (the fuel pump don't need pressure to work, the fuel pump need fuel inside to work, not AIR . Don't confuse the fuel pump with the injection pump. The fuel pump it's inside the injection pump in this Bosch vp 44. The retun hose are conected directly to the fuel pump by that overflow valve. So if you have any leaking on the return hoses , that leaking will fill with air your fuel pump , throug that small hole (the blender). Check any leakage by filling the return hoses with compress air. (And of course check the one way valve on the fuel filter olso with compres air ). You can check all the injections likege at once assuming that the one way valve is working properly: take out the fuel hose from your fuel tank , (turn and return) fill with compressed air the turn hose , and block the return hose. If you have broken hose you should heare or see it. (The metal pipes can't be checked this way because of the pressure valve from injection) . Again don't confuse the fuel pump with injection pump.

[@bobbarrett1164]

I am a technical Automotive Instructor and was very impressed by your presentation. Great camera work and clear concise speech even though your first idea didn't fix it. Thanks!

[@DAMIANFMARTI15]

A similar problem i was having with my 99 24v brought me to your video. I was having a massive fuel leak coming from what I though was the check valve but it turn out it was the fuel return line that had a hairline crack in it due to vibration. This video is old but very helpful. If it weren’t for you giving me the idea to follow the lines I would’ve been swapping out my injection pump for no reason! Lol

[@AllThingsBoost]

Glad you found it! That's wild

[@kevinaweseom2866]

Keep us updated

[@NickDeWalt]

Mine does that too. Not nearly as bad. But if you let the lift pump run longer mine will fire right up. I’d like to see your double din radio in that dash too. Been wanting to put one in mine but curious how it looks

[@alexc7641]

This just happened to me. Luckily I was able to find the root cause of the problem with the help of a member on Facebook group 2nd gen cummins. I had a crank no start situation. I had a constant 14-15psi to the inlet of the vp44, i had no check engine either, and the cranking sounded normal....didn't sound weak as if the batteries were dying. The first method that allowed me to crank and fire up the engine as it would normally do it was by cracking a few fuel line, #1,3 and 4. Once the engine started fuel started coming out so i snugged them back up. The 2nd method was by only bumping the starter (this allows the lift pump to accumulate 15psi of fuel pressure) then i would unplug the lift pump relay mounted on the firewall then go back in and start the engine up..then go back and plug in the relay again. sounds like theres an exccesive psi build somewhere that is not allowing a successful start. This is frustrating....i cant be doing this all the time and i know i can proably hook up a toggle switch temporarily to turn the lift pump on and off for this procedure. Let us know what you found.

[@AllThingsBoost]

I have a relay installed in mine, and what is does is cut the lift pump when the key is turned to the start position. Basically its got 3 wires, 2 are the input and output for the power wire to the lift pump, and the 3rd is to anything that will have constant power but cut when the engine turns over (Mine is run to a window regulator fuse). So that way it turns off when the truck turns over to keep that pressure minimal during cranking.

[@alexc7641]

My VP just went out yesterday...engine wouldn't start by removing the relay nor crackin the fuel lines. Then I plugged in my other OBD scanner torque pro and it gave me the P0216 code which is basically the death code for the VP...so I guess you might be getting the early symptoms of the VP failure...this was my first vp going out ever

[@AllThingsBoost]

@@alexc7641 I hope not. I havent had any issues since installing my inline check valve right after my lift pump. Did another vid on that one

[@juddrush3102]

I just purchased a 99 24 valve with 205k miles on it. Found your video by trying to chase a fuel leak... I noticed my dash lights all lights up when turning key to accessory, then lights go out, wait another 5ish seconds and the "wait to start" light appears. I then wait till that light goes off and it fires. Your 01 light sequence might be different but I have to keep the key on accessory till lights go off, then "wait to start" appears... Hope you got'er running!

[@AllThingsBoost]

Congrats on the truck buy. I did fix it, turned out to be the injector crossover tubes. My wait to start I found only kicks in when the air temp is lower than 65, otherwise it doesnt activate the grid heater. Been 18 out recently and working fine. Thanks for the comment though, appreciate you

[@davidbulich1254]

The wait to start light should always come on right away even if for a couple seconds if it doesn't you have ecm problems

[@cesargarduno7999]

Mine had this problem it turned to be the cam sensor that it would work intermittent. Replaced and been good fires up on the spot replace with oem.

[@ronniephipps6555]

If it's ok how did you know your cam sensor was going bad?

[@cesargarduno7999]

@@ronniephipps6555 Rpm needle does not move when you crank.

[@octane_fueled_gaming9159]

im having a problem where once truck is at running temp it dies and will not start without bleeding injector lines but will only run about half mile before it dies again. keep in mind if i let the truck cool off completely its will start and run with no issue untill it gets to running temp again any ideas would be great. truck has brand new lift pump other than that its all stock original parts

[@AllThingsBoost]

I'd look into a potential VP44. I havent had one fail personally, but from my understanding when the electronics start going out it's due to when the pump warms up and usually has issues when the truck it warm. Other than that I'm not sure

[@mannyc6585]

I had the same problem, too much fuel pressure will cause the check valve to open up and not let fuel flow to injectors which will cause a hard start.

[@AllThingsBoost]

Generally you don't want to run any more than 20psi of Fuel pressure or you can hurt the VP44 internally. The check valve is meant to maintain up to 14 psi of fuel pressure for the VP44 to use to keep what you just described from happening. Any more doesn't mean the fuel isn't getting to the injectors, it just means the excess is bled off through the return. The only way I could see your scenario playing out would be if the check valve was stuck wide open. The VP44 separates the high and low pressure side. As long as fuel is flowing to the VP it will send it to the high side and the injectors.

[@noneya8184]

Turn the key on with out starting it and see if the lift pump is running behind your fuel filter . If it's not shut the key off and turn the key back on just enough to bump the starter and let off leaving the key in the on position and check and see if the lift pump is running if not hook it straight to the battery and if it don't run go get a new one.

[@Mr.Atwood]

Question I replaced the batteries and vp44. When I try to crank the truck it won't send fuel to the lines also sounds like a remote control car. What am I missing here besides air in the lines would there be another issue I need to fix if so what do you think it is?

[@AllThingsBoost]

I'd check to see if the VP44 is being supplied fuel by the lift pump. If it is stock, bumping the key should turn on the lift pump for a few seconds. Ideally you want between 14-20 psi to the VP44 at all times when running. If you don't have a fuel pressure gauge, get one to ensure it is not starving the VP44. It used fuel for cooling as well, so more is better to a point.

[@bolle8140]

Same here.. with a p0216

[@AllThingsBoost]

I also had that code with this issue, turned out to be leaky injector crossover tubes not sealing to the hard lines, after replacing them all is good.

[@BDG1776]

Mine did this and it was an injector bleeding out. Check your oil to see if your level is high

[@AllThingsBoost]

Havent seen any oil level rise, but you might be onto something. As far as I know these are the original injectors, probably wouldnt hurt to get them swapped out sometime soon

[@cph3459]

It would have to be on the pressure side of the line, the return is after the engine and wouldn’t cause your issue

[@holtman2598]

I know this video is old, but where did you get it from?

[@AllThingsBoost]

I think it was from thoroughbred diesel

[@holtman2598]

@AllThingsBoost holy cow man, I had no thought of an answer on this old of a vid, thanks so much for answering. After I made this comment, I fixed my long crank 😀 😄

[@kevinaweseom2866]

Same problem man except mine doesn't catch it just takes forever on mine

[@AllThingsBoost]

From everything I've been researching on this, no catch at all would point me towards injectors or their seals such as cross over tube o rings, sounds like your high pressure side isnt building or maintaining prime

[@kevinaweseom2866]

@@AllThingsBoost im not making oil, and it doesn't have long cranks everytime its crazy weird , was going to try that check valve if you have the link or part number

[@AllThingsBoost]

This is a link to the check valve for the VP44 I installed in this video. zzdiesel.com/magnum-1998-5-2002-5-9l-cummins-vp44-overflow-valv/?gclid=Cj0KCQjwvb75BRD1ARIsAP6LcqvsA8Rw0ytl1ZhDKC6xDL37Mnl8P9SWFOe7XohO7_qkeK8l09XR9XsaAiLLEALw_wcB

[@original6nation]

Did you check the rear banjo bolt and T fitting at the back of the head

[@AllThingsBoost]

I did the rear banjo bolt, no visible leaks from the T fitting, I have to T seals to install eventually, just haven't gotten to it. I seemed to have gotten a work around with using a check valve in the feed side post lift pump. I realize its not the "right" way to fix it, but until I find a visible leak its good enough for me

[@original6nation]

I've had to remove injector lines and run air there them before might be a line that's causing it but just a idea

[@Th3XC45T]

Lol if the part ships to canada. Spent a month looking

[@terrenceyozie250]

Sounds like a crank shaft sender!!

[@AllThingsBoost]

Low pressure fuel line was losing prime

[@jacobwhittaker2790]

@@AllThingsBoost so you found an actual fix?

[@TheFpvt]

@@AllThingsBoost Hi, where was losing prime? how did you fix it? thanks

[@AllThingsBoost]

@@TheFpvt I fixed it by replacing my injector crossover tubes. It was leaking where the high pressure VP44 lines meet the crossover tubes at the head.

[@TheFpvt]

@@AllThingsBoost crossover or leak off tubes? waere those high pressure in metal?

[@johneytaylor9319]

Vp I’d not having it

[@AllThingsBoost]

Turned out to be a fuel leak at the head. VP still going strong

[@smokeymtnforge7444]

Try not just starting it. It is a diesel turn the key over till light goes out then start

[@doncobb9451]

If you bump your engine twice before starting ,as I'd your priming your fuel filter, the engine should start. Good luck. Lol