Replaced ORIGINAL VP44 with rebuilt unit less MPG & Power!!

[Michaelsloft]

All of this is not good news. It takes considerable time for this project and to see these results after installation is very disappointing. I sure hope it gets figured out.

Dave

Dave, it has been very disappointing after carefully installing the rebuild pump. Paid extra detail to every fastener & part along the way with the thought of having renewed power, performance, drivability and even more MPG as I had the first 200,000 miles. MPG and performance was ever so slightly less from 200,00 to 250,000 miles. I'm not going to give up for a while and with the support of TDR members will hopefully get it figured out.
I'm not familiar with the Oilguard Bypass System? If you have any information or photos of install would like to learn more.
Thanks for your input and support.

 

[Michaelsloft]

Guess I got lucky? Got my VP from Thoroughbred. I agree = considerable time and money for this project and to net results Michael has experienced sucks! Staying tuned and hoping my VP lasts forever...

Joe,

I've heard good things about Thoroughbred and glad to hear it worked out for you. It was my first injection pump install and even though it went smoothly and I enjoyed the process it was a big effort and expense. Not getting any younger! My original VP44 lasted more than 250,000 and many hours of use. Thanks for your input and support. Hope your replacement pump last forever too.....

 

[DavidC]

Dave,
I'm not familiar with the Oilguard Bypass System? If you have any information or photos of install would like to learn more.
Thanks for your input and support.

http://ecomicrofilters.com/eps-20-dc.html

It has served me well over the years, the screw on can is very sturdy and you need a strap type wrench to remove/install. Mine was installed probably about 15 years ago, the filter is fed from the extra plug at the engine filter and is returned to the oil pan. The newer ones I believe return to the oil fill cap. It is installed on the front cross brace on the passenger side just behind the radiator and has a petcock on the top for taking oil samples etc.. I also used that valve to make sure I had oil pressure/flow when my sender decided to go south one morning.

Dave

 

[Michaelsloft]

http://ecomicrofilters.com/eps-20-dc.html

It has served me well over the years, the screw on can is very sturdy and you need a strap type wrench to remove/install. Mine was installed probably about 15 years ago, the filter is fed from the extra plug at the engine filter and is returned to the oil pan. The newer ones I believe return to the oil fill cap. It is installed on the front cross brace on the passenger side just behind the radiator and has a petcock on the top for taking oil samples etc.. I also used that valve to make sure I had oil pressure/flow when my sender decided to go south one morning.

Dave

Dave, thanks for the detailed information about use and installation. I'll check out the link. Thanks again....

 

[KATOOM]

Michaelsloft, I just ran across this thread and it looks like you've gotten some pretty good feedback so far.....

Yes, as you pointed out, your truck is the rare SO with the 5600. Definitely not many were built, and if you ever need to touch the clutch or transmission, you probably already know that you have the smaller clutch and 1-1/4" input shaft too.

Nonetheless, the difference in the SO and HO VP's was mostly because the HO trucks squeezed a little more hp/tq out of by adding more timing to the injection pump, more fuel line pressure and injectors popping under higher pressure. This is why when people are trying to some quick easy power out of their trucks the SO's respond best to fuel timing boxes and HO's respond best to higher flow injectors.

What you could do, if you dont already have one, is put a timing box on your truck and see if your performance is restored.

Also, have you ever adjusted your valves? 150k miles is around the time you should see if they need to be snugged back up, and people express restoring some crispness in the throttle when doing so.

Also, 250k miles doesnt mean worn out injectors but they can show their age if they're still stock and have been run for the past decade on ULSD. Remember, the 2nd gen trucks were not designed with ULSD in mind and its been proven over and over that todays diesel does not carry the same lubricating properties as what was available when these trucks rolled off the assembly lines.

One more thing I would highly suggest checking is the alternators AC voltage output. Very easy to confirm with a voltage tester that reads in DC and AC. Excessive AC voltage is detrimental to sensitive electronics neighboring and can over time cause issues. Something found to be the cause of erratic cruise control, FPCM issues, hunting automatic transmissions, etc... Again, 250k miles on the stock alternator could be generating more AC voltage than you know.

 

[Michaelsloft]

Michaelsloft, I just ran across this thread and it looks like you've gotten some pretty good feedback so far.....

Yes, as you pointed out, your truck is the rare SO with the 5600. Definitely not many were built, and if you ever need to touch the clutch or transmission, you probably already know that you have the smaller clutch and 1-1/4" input shaft too.

Nonetheless, the difference in the SO and HO VP's was mostly because the HO trucks squeezed a little more hp/tq out of by adding more timing to the injection pump, more fuel line pressure and injectors popping under higher pressure. This is why when people are trying to some quick easy power out of their trucks the SO's respond best to fuel timing boxes and HO's respond best to higher flow injectors.

What you could do, if you dont already have one, is put a timing box on your truck and see if your performance is restored.

Also, have you ever adjusted your valves? 150k miles is around the time you should see if they need to be snugged back up, and people express restoring some crispness in the throttle when doing so.

Also, 250k miles doesnt mean worn out injectors but they can show their age if they're still stock and have been run for the past decade on ULSD. Remember, the 2nd gen trucks were not designed with ULSD in mind and its been proven over and over that todays diesel does not carry the same lubricating properties as what was available when these trucks rolled off the assembly lines.

One more thing I would highly suggest checking is the alternators AC voltage output. Very easy to confirm with a voltage tester that reads in DC and AC. Excessive AC voltage is detrimental to sensitive electronics neighboring and can over time cause issues. Something found to be the cause of erratic cruise control, FPCM issues, hunting automatic transmissions, etc... Again, 250k miles on the stock alternator could be generating more AC voltage than you know.

KATOOM, thanks for taking the time to read this thread and sending some good ideas my way. And yes, I have gotten some good feedback along with some very good ideas to correct this issue with a rebuilt VP44.

Since I have had the truck since new for 18+ years now I've being en able to learn a few things about the SO NV5600 and have tried my best to stay on top of maintenance over the years. Always more to learn and learning more from will informed TDR Members! Fortunately no issues with the clutch at this point with more than 251K and overall the truck has been amazingly reliable and efficient up until the VP44 failure.

Just to confirm - Immediately after installing the rebuilt SO VP44 I noticed the engine was significantly quieter, smoother and running cleaner too with virtually no smoke on start up right after bleeding the fuel system. My initial "gut feeling" was less fuel line pressure, and less timing! So after a short warm-up checked all the lines etc. The pump is installed correctly with no issues in the fuel system etc.

I have never used a timing box or tuner on the truck and would like to see if there is a way to correct the issue without adding a Smarty or similar. I am working on a few ideas from fellow TDR members and will have time to pursue them later this week.

The truck was performing very well before the VP44 and showed no signs of needing a valve adjustment nor does it currently. The valves were checked and adjusted at 148K and I was planning on checking them again this Spring/Summer anyway now that I'm over 250K.

As far as injectors go - it idles smoothly and does not show signs of worn injectors. I used Stanadyne Performance Formula from day one when I drove it off the dealer lot, broke it in with a 5 gallon can of Stanadyne for about 40K and have used PD Diesel Kleen in every tank of fuel since. And I think this helped to get 250K out of the original VP44! It still ran well as I have mentioned and I think heat & heat cycles from use finally killed the PSG/electronics.

Great idea suggesting to check alternator AC voltage. I replaced the original Bosch alternator at 226K with a rebuilt unit directly from Bosch in California and checked it soon after installing the rebuilt VP44. It is only putting out 0.016 to 0.021 AC volts on a Fluke 16. It is charging and operating properly.

Going through these details is helpful and if you think of any additional things to check please send them my way.

I'm determined to get the truck performing the same it did for the the first 250K and planning on driving it at least another 250K.

Thanks again for your input.

 

[KATOOM]

Well it certainly sounds like you're exploring any and all options trying to figure this out..... And given the lengthy detailed effort you've invested in solving your issue so far, I'm going to lean towards the VP simply being the culprit.

Its been awhile since I've touched this topic too but without a doubt the problem with low quality rebuilds were an issue 2 years ago just as much as they were 15 years ago. I dont know why either since there's only a handful of reman companies out there who actually own a Bosch 815 bench. I remember the main reason for poor rebuilds was reused PSG units were being used merely because they still worked. Yes the new bar codes should indicate the age of the PSG but whether or not the unit is/was "brand" new, or even the correct unit, is still a possibility.

That said, did you investigate all the stamping codes on the VP housing as well? Not that it would likely bring anything to light, but ya never know. Nonetheless, I think given what you've done so far you may want to just demand another VP.

 

[Michaelsloft]

Well it certainly sounds like you're exploring any and all options trying to figure this out..... And given the lengthy detailed effort you've invested in solving your issue so far, I'm going to lean towards the VP simply being the culprit.

Its been awhile since I've touched this topic too but without a doubt the problem with low quality rebuilds were an issue 2 years ago just as much as they were 15 years ago. I dont know why either since there's only a handful of reman companies out there who actually own a Bosch 815 bench. I remember the main reason for poor rebuilds was reused PSG units were being used merely because they still worked. Yes the new bar codes should indicate the age of the PSG but whether or not the unit is/was "brand" new, or even the correct unit, is still a possibility.

That said, did you investigate all the stamping codes on the VP housing as well? Not that it would likely bring anything to light, but ya never know. Nonetheless, I think given what you've done so far you may want to just demand another VP.

Katoom, anticipating a VP44 failure at some point in my '99 I followed and reading/following Cummins over the years I felt confident in the Bosch certified 815 bench equipped rebuilder I selected. I have not mentioned the Company nor the retailer due to the chance that it might not be a VP44 issue. The rebuilt pump is supposed to have a NEW PSG and is a 2 year Warrantied unit. And when all options have been investigated/examined it may require my demanding another VP to restore performance. I would rather not have to remove the VP and install another one, but it that is what it takes, I'll carefully do the removal/installation again!

I've double and triple checked the stamping codes on the VP housing and took photos of the original and rebuilt unit side by side. All the numbers match and add up to what is the correct part.

I'll post anything I learn in the process of getting my truck to run properly and in the meantime may have some more questions.

Thanks again.

Michael

 

[lpagano]

I had the same problem on my 2001 3500 HO NV5600 4WD. I never got a reasonable response from the supplier or Blue Chip Diesel (both are supposed to be reputable). I checked everything and found nothing! I solved the problem by trading in the 2001 on a 2018 3500 CCLB 4WD Aisin with 4.10 gears.