Can a vp44 have too high of pressure

I have only seen two problems from high pressure.
1) seen one where the guy had 30+ psi and it pushed the front seal out and filled his crankcase with fuel...this guy was a moron and brought the truck to me for a "fuel leak" which just happened to be from the crankcase being full and pushing Tappet cover gasket out. Good job there...needed a motor.

2) have seen high pressure cause hard starts when the truck was warm. Drop the pressure below 14psi and all those trucks start when warm.
 
YoungDiesel27 said:
I have only seen two problems from high pressure.
1) seen one where the guy had 30+ psi and it pushed the front seal out and filled his crankcase with fuel...this guy was a moron and brought the truck to me for a "fuel leak" which just happened to be from the crankcase being full and pushing Tappet cover gasket out. Good job there...needed a motor.

2) have seen high pressure cause hard starts when the truck was warm. Drop the pressure below 14psi and all those trucks start when warm.
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That's crazy, my pressure is not that extreme
 
It doesn't always act up, that's what is weird. I can drive it, and park it for a while. Come back and drive off and it goes crazy. Idle goes to crap, no throttle, a little white smoke, with a lot of jerking and chugging, and then it dies. Then the start up right after is a successful fail! The lift pump never fails, I hard wired the relay as an option to try out. This only makes it harder to start. If you wait for a 10 -15 mins it will crank right up and drive like nothing ever happened.
 
AHall said:
Sounds like timing failure.
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Well give me some pointers please. I mean what else could it be? Especially since it doesn't do it all the time. I'm on wits end, granted I'm still tempted to check the harness
 
aggies12 said:
Well give me some pointers please. I mean what else could it be? Especially since it doesn't do it all the time. I'm on wits end, granted I'm still tempted to check the harness
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I'd start by checking the key. There should be a key number stamped into your new pump. Verify your key has the same number, isn't damaged and the arrow is toward the pump.
 
AHall said:
I'd start by checking the key. There should be a key number stamped into your new pump. Verify your key has the same number, isn't damaged and the arrow is toward the pump.
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This is good advice. To the OP, in one of your posts you said you used the original key. The re-man pump should have come with a key, and that is the one that you should have used. As stated above the number on the key should match the number on the pump.

Paul
 
MAXTORQ said:
Unless your a builder you know squat yourself. Built plenty of these pumps and I'll argue to the end while there maybe a handful of people running those types of pressures much any pressure over 14.5 will push fuel past the front pump seal and does some crazy things to a pump. Don't believe me watch one on a test stand sometime.

Those types of pressures are good for strip truck running stupid amounts of fuel out an injector causing to drain the pump, but on the street its useless.
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Hmmm. Agree to disagree. I don't know of anybody with an aftermarket lift pump running less than 15 psi. The latest theory is to keep the pressure above the bypass setting of 14 so fuel is always running through the pump instead of dead heading to assist with cooling and lubrication. I remember in the early days guys said it would cause a hard to no start condition. Never experienced that. Next time a pump does it on the stand video it and show us. Why is the pressure at fault, and not a pump defect? I would think if pressure were at fault then all of the pumps would act similar on the stand.

aggies12 said:
Well give me some pointers please. I mean what else could it be? Especially since it doesn't do it all the time. I'm on wits end, granted I'm still tempted to check the harness
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Back to the subject. If you are not 100% certain you used the key that came with the pump and that it is oriented correctly, then start there. If you keep changing variables eventually you will have multiple troubles masking each other. No way in he!! I would be changing out a harness or ECM unless I had some very solid proof one or the other was at fault. Didn't you state you got an ECM from Cummins? That seems odd to me as well. Last I recall Cummins would not touch them. Made you go to Dodge, possibly because it is Dodge "tuning" their hardware. I don't seem to remember seeing the ECM on quickserve either.
 
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I stand corrected. 3942336RX for the ECM. I even found the Chrysler software. Wonder why guys were saying only Dodge could do it? So you should have a solid ECM.
 
Yes I'd agree, I'd agree my original was good too. Just went on a limb with it. With the timing issue, don't you think it would do it more frequently? To be honest, with the key I'm pretty sure there wasn't one in the box.
 
Ok so what key did you use? If you used the key out of the other pump then it's a safe bet to say that the key you have in it now does NOT match the pump. The pump is stamped along with the key. And they have to be the same.
 
Yes, if the pump and key number don't match that is most likely the issue. Get the number on the pump and if your pump shop doesn't have one, I'd be happy to ship you the correct key.
 
The key should have been pressed into the shaft of the pump.
 
weazel said:
The key should have been pressed into the shaft of the pump.
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Hey weazel, johnny installed this pump, I'm sure he got the right key. I'm pretty positive there was a key in that shaft. The pump came from m&d distrbutors. If not the key, what else could it be?
 
aggies12 said:
Hey weazel, johnny installed this pump, I'm sure he got the right key. I'm pretty positive there was a key in that shaft. The pump came from m&d distrbutors. If not the key, what else could it be?
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Ok, the pump was installed at a reputable shop. Maybe have him set the pump key to tdc on the gear, then slide the pump back to verify the numbers on the key like these guys are saying. It won't be the installation, as Johnny has installed a butt load of these pumps. I am curious to see if the pump builder might have stuck in a different key, by accident or just did it to have one in there...

Have you checked the wiring on the pump to verify no chaffing?
 
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