Slight stutter upon startup occasionally

[YeaImDylan]

Hey all, title says most but will go into more detail.

 

sometimes on startup, the engine will start, then die for half a second and come back on. Like if you were to turn the key off while running and quickly turn it back on. This happens occasionally and then a few weeks ago, it would start and then die after a few seconds. It did this a few times before it was just cranking. Finally got it started and it ran fine. This has all occurred after my o Reilly vp pump replacement … and I’m definitely worried it’s the pump. Any insight is appreciated!

[Tractorman]

When the stumbling and dying occurs, does it happen after the engine has been shut off for a long period of time?  If so, there is a possibility that air is entering the fuel system somewhere, maybe related to the R&R of the VP44. 

 

Did you perform any other work when you replaced the VP44?

 

Are you getting any trouble codes?

 

- John

[YeaImDylan]

4 hours ago, Tractorman said:

When the stumbling and dying occurs, does it happen after the engine has been shut off for a long period of time?  If so, there is a possibility that air is entering the fuel system somewhere, maybe related to the R&R of the VP44. 

 

Did you perform any other work when you replaced the VP44?

 

Are you getting any trouble codes?

 

- John

No other work, just the VP along with oil change cuz it dumped 2 gal of diesel into the crank case 🤬

 

The fuel line is a bit old and there was a visible crack on the outside rubber BUT no leak under pressure.. so I don’t think air would get in there. I don’t see any leaking lines connected to the VP either (like return and whatnot). I’ll check the back of the head banjo bolt and see if it’s moist. Last time I had that come loose I had hard starts but none of this weird stutter I get after replacing VP.

[QuadRunnerJake]

Doesn't matter if it's not leaking fuel. Diesel needs a much larger space to weep from than air needs to get in. Replace any lines with visible cracks, make sure the fittings are secured (i used hose clamp over the push lock fittings) also recommend replacing  copper washers on the VP where the return and supply lines are. Check all connections to make sure they are tight but do not over tighten! That's all the advice I got. We seem to get paranoid about VP failure once it happens when in reality the current iterations of the VP are quite reliable.

 

   I did blow up a VP under warranty one time but that was because the fass pump seized and starved it for fuel. I was able to hide the fact it was wire tapped with a posi-tap by melting a small amount of black plastic from the top of a black spray paint can over the small puncture created by the posi. Then I lightly marred all the wires with pliers to match the look of the tapped one making it indistinguishable from the others.

[YeaImDylan]

24 minutes ago, QuadRunnerJake said:

Doesn't matter if it's not leaking fuel. Diesel needs a much larger space to weep from than air needs to get in. Replace any lines with visible cracks, make sure the fittings are secured (i used hose clamp over the push lock fittings) also recommend replacing  copper washers on the VP where the return and supply lines are. Check all connections to make sure they are tight but do not over tighten! That's all the advice I got. We seem to get paranoid about VP failure once it happens when in reality the current iterations of the VP are quite reliable.

 

   I did blow up a VP under warranty one time but that was because the fass pump seized and starved it for fuel. I was able to hide the fact it was wire tapped with a posi-tap by melting a small amount of black plastic from the top of a black spray paint can over the small puncture created by the posi. Then I lightly marred all the wires with pliers to match the look of the tapped one making it indistinguishable from the others.

Thanks for this! I will replace that main fuel line! Also thanks for the warranty hack lmfao my issue is now tho I need a damn VP top cover… blue torque sealant I can get my hands on for the bolts tho. Old vp p/o had on with stealth tap and I wanted my core charge back so I had to tap this vp and put the shiny new cover on the dirty *** hotrod pump I had lol