Bad vp44

[madsen]

So my vp44 is going bad. I am having dead pedal issues and its having idle problems and occasional white smoke at start up.

History 98 dodge 24 valve replaced the vp 48 months ago at 180k miles, now has 198k miles. It had no start issues after getting warm and would start after pouring 5 gallons of cold water on it . I did the first replacement myself but could never get the truck to start and run so loaded the truck and took it to the shop and they replaced the vp44 with another one and it ran. The rebuilder diagnosed the first build as bad and paid the shop bill to replace it.

That gets us to the present. The truck has following upgrades DP fuel lift pump in standard location. It has a secondary fuel filter just before the DP pump as required for the warranty. It has new Bosch RV injectors and a fuel pressure guage mounted on the factory fuel filter in the engine bay. It holds 19-20  pounds of pressure at idle and drops to 12 at WOT. 

I have run mostly Cenex road ranger ( has a higher lubricity number than Bosch requires)  fuel since putting on the new vp and have added 2 cycle oil as recommended when I cannot get the cenex diesel. The truck does almost no pulling and runs well.

I got 21 mpg on my last round trip to southern oregon 2 k miles before these issues started. The retailer who sold me the rebuilt vp44 says the pump is out of warranty 

I could send it in and have just the worn out parts replace at probably half the cost of a full rebuild but then the warranty would only cover the replaced parts.

I am wondering if the rebuilder is the problem or do I need to do more upgrades to my truck to prevnet the problem again

I am not willing to replace the pump myself this time and have a few other issues to resolve so am looking at a bill of 2k for getting a rebuilt vp44 installation and the other issues fixed ( the vacuum pump steering pump is leaking engine oil )

Thinking I should get a big line kit installed from fuel filter to injection pump as a fix to keep from having a second vp44 failure.

The pump rebuilder is Industrial Injection out of Salt Lake and the shop doing the work is Gomers out of Missoula

 

Thanks for taking the time to read my long post and sharing your thoughts.

JOHN

[Mopar1973Man]

46 minutes ago, madsen said:

It holds 19-20  pounds of pressure at idle and drops to 12 at WOT. 

 

Too low the overflow valve closed at 14 PSI. You lost your cooling and lubing of the pump causing wear. You need to stay above 14 PSI for longevity. You pump doesn't have enough volume an/or your supply plumbing is too restrictive causing the pressure drop. You should have 1/2 inch lines from the fuel tank to the lift pump to the factory filter then one more between the filter and the injection pump. I'm set at 17 PSI with a Quadzilla (+180 HP), DAP 150 HP injectors (7 x 0.010) I only drop 2 maybe 3 PSI. Settle right at 15 PSI typically all the way to 100 MPH. 

46 minutes ago, madsen said:

am wondering if the rebuilder is the problem or do I need to do more upgrades to my truck to prevnet the problem again

 

True rebuilder should have a Bosch 815 test stand to do a proper rebuild of the pump. Yes a personal can change the parts in the pump no problem. The next step is to put the VP44 on a Bosch 815 test stand for 3 hours to tested fully and have the PSG reflashed with the calibrations. This is a requirement. Also Ive been total true Bosch rebuilder will not reuse a PSG unit on the pump it must be replace according to Bosch policies. 

 

 

Here is my list of certified shops.

 

 

As for fuel system you need a better fuel system and keep your fuel pressure above 14 PSI at all times to keep return fuel flowing. I'm running an AirDog 150 with a 4G AirDog 165 pump. This setup is 14 years old and still going. I lost my first pump at 250k miles, 3G pump failed instantly in 3k miles, now 4G pump is solid and works awesome no issue to report. Never gelled in 18 years still going... 

Edited September 22, 2020 by Mopar1973Man

[madsen]

Ok so Industrial Injection is on your list of rebuilders who have the Bosch test/calibration stand.The DP lift pump I have is considered to be an appropriate pump for a non modified truck !

I believe if I remember correctly your VP44 pump came from a Salt Lake City rebuilder most likely Industrial Injection.

You make reference to a PSG when discussing a pump. What is that part ???

JOHN

[Me78569]

psg is the computer on top of the pump.

 

18k miles is terrible pump life.  I am more likely to say that you go a bad pump from the getgo. 

[Mopar1973Man]

4 hours ago, Me78569 said:

psg is the computer on top of the pump.

 

18k miles is terrible pump life.  I am more likely to say that you go a bad pump from the getgo. 

 

Yup I'd have to agree...

[Alexio Auditore]

Not to throw a wrench in it, but unless he drives around at wot at all times, there is no way that is what caused his to fail. Ive been running the standard fuel line up to the lift pump(Raptor 100), with ½ inch lines from there to filter, and ⅜ inch to

the vp, and still only have 8-10psi at wot. Been this way for almost nine years, and I believe its the factory vp44 at 262k miles. I cruise 65-70 at 15psi. 

By all means, if you can keep psi above 14 at all times, then do it especially if you drive it like you stole it all the time, but dipping down below it for short burst, especially only down to 12, i think that is pretty good.

 

I agree with the guys above, sounds like it was a bad vp from the start. I think its recommended on this forum to work the vp hard the first year(under warranty ) because if its going to fail, it should fail quick.

[wil440]

14 hours ago, Alexio Auditore said:

Not to throw a wrench in it, but unless he drives around at wot at all times, there is no way that is what caused his to fail. Ive been running the standard fuel line up to the lift pump(Raptor 100), with ½ inch lines from there to filter, and ⅜ inch to

the vp, and still only have 8-10psi at wot. Been this way for almost nine years, and I believe its the factory vp44 at 262k miles. I cruise 65-70 at 15psi. 

By all means, if you can keep psi above 14 at all times, then do it especially if you drive it like you stole it all the time, but dipping down below it for short burst, especially only down to 12, i think that is pretty good.

 

I agree with the guys above, sounds like it was a bad vp from the start. I think its recommended on this forum to work the vp hard the first year(under warranty ) because if its going to fail, it should fail quick.

All I can say is I've done a lot of testing on my truck over a period of weeks and my FP at idle is 8 to 9 psi rising to 25 psi at 2k. I removed the return from the basket to check for return flow, I expected none but found a good substantial amount and I found If I restricted this return a little FP rose high enough to blow the face off of my FP gauge. 

My fuel temperature never goes over 120f and it takes forever to get there. 

I must add my fuel system has nothing stock now except the vp 

I have replaced the overflow at the vp with no difference 

Doing more testing and reading the vp manual to figure out what is going on