Safe fuel pressure

[gassernomore]

Not to defend him or nothing, but he does recommend the Fass DDRP for longer life.

Look at it this way: stock pump, auto store pumps, DDRP, mechanical pump, FASS-AirDog-Raptor pumps. The further away from stock pump the longer it will last plus the better service you will get out of the VP. I suppose you could also add the particulates in the fuel into the mix as well. The more particulates and a poor fuel filter will mess up both pumps as well!

[guesswho512]

i wasn't trying to bad mouth anyone. but that info is on that site. you paid for that pump...i'm not the one going to tell you what you can and cannot do with your property, but even wise Cummins said 10psi minimum at any load! i personally believe that you need to have fuel "carry" the heat away. its like the cpu in your computer. it might boot up for a couple of seconds with no heatsink...but in a minute you will know what burnt silcone and copper smells like! run a VP44 with minimum cooling....your going to know what a empty wallet feels/smells like!

[Mopar1973Man]

Little rough around the edge but... The point is valid...

We all know the Vp44 injection pump runs without a lift pump. How many times do we tell people to install a fuel pressure gauge to find out they report 5 PSI down to 0 PSI. This far to common to see... Typically the owner changes the lift pump quickly with another stock pump hoping to fix it. But typically the pump starts spitting codes out like P0216 and others...

The point here is at what pressure do you get the most life from a VP44?

None of use are worried about the minimum pressure that creates MAX horsepower... Very few of us here even go out racing. But is the whole Blue Chip article there is nothing said about maximum lifespan, testing in regards to lifespan, extended dyno testing for lifespan. Just nothing...

[Hood Latch]

Little rough around the edge but... The point is valid...

We all know the Vp44 injection pump runs without a lift pump. How many times do we tell people to install a fuel pressure gauge to find out they report 5 PSI down to 0 PSI. This far to common to see... Typically the owner changes the lift pump quickly with another stock pump hoping to fix it. But typically the pump starts spitting codes out like P0216 and others...

The point here is at what pressure do you get the most life from a VP44?

None of use are worried about the minimum pressure that creates MAX horsepower... Very few of us here even go out racing. But is the whole Blue Chip article there is nothing said about maximum lifespan, testing in regards to lifespan, extended dyno testing for lifespan. Just nothing...

Mopar Man, Your question: "THE POINT HERE IS AT WHAT PRESSURE DO YOU GET THE MOST LIFE FROM A VP44?" and the ultimate correct answer should ( I believe ) be the GOLD STANDARD for this subject. In my opinion, your question could not be worded any better than that.

[Mopar1973Man]

Thanks... That's what I'm after really... I've been through all the forum like CF.com and other and been beat down with all the race nuts quoting that line out of Blue Chips site... But what I realized there is 2 class of truck owners... 1. High performance / Racing/ Dyno Queen / Sled Puller2. Daily driver & Grocery getter.I found that there is way to much hype for the performance crowd and very little out there for the common Joe that drives to work and back home every day. Might drag a trailer on the weekends but basically the truck is light duty. Like myself my truck see a bit more than light duty and I skid logs, haul firewood, tow trailers full of firewood, etc. So getting back to the the BC comment is that has there been any kind of testing in this type of driving? (I can bet not!)So I think what we need to do is keep track of the fuel additives, fuel pump (names), fuel pressure, and lifespan of the VP44 and I bet you find there is a different amount of failure compared to the performance site are saying... :whistle:I know ol' JL Welding would jump on this signing the blues...:rolleyes:Another good question...."How do you get the most out of your VP44 lifespan?"

[flman]

I went through 3 stock lift pumps in a years time...............

[gassernomore]

I went through 3 stock lift pumps in a years time...............

Not to rag on you personally. But, with 3 lift pumps in 1 year is why it is preached to buy one of the premium pumps. We all know money is tight but sometimes it is better to spend more at the start, then to go the cheap route. On a side note, flman you don't have to buy another pump now it is LIFETIME warrantied!

[Hood Latch]

thanks... That's what i'm after really... I've been through all the forum like cf.com and other and been beat down with all the race nuts quoting that line out of blue chips site... But what i realized there is 2 class of truck owners... 1. High performance / racing/ dyno queen / sled puller 2. Daily driver & grocery getter. I found that there is way to much hype for the performance crowd and very little out there for the common joe that drives to work and back home every day. Might drag a trailer on the weekends but basically the truck is light duty. Like myself my truck see a bit more than light duty and i skid logs, haul firewood, tow trailers full of firewood, etc. So getting back to the the bc comment is that has there been any kind of testing in this type of driving? (i can bet not!) so i think what we need to do is keep track of the fuel additives, fuel pump (names), fuel pressure, and lifespan of the vp44 and i bet you find there is a different amount of failure compared to the performance site are saying... I know ol' jl welding would jump on this signing the blues... Another good question.... "how do you get the most out of your vp44 lifespan?"

I agree. Honest and accurately compiled data (on the items you mentioned) over a reasonable amount of time should give us the definitive answer to this subject. While we are all entitled to our opinion, we should not ignore the facts once they present themselves.

[flman]

It was not about money, it was more a lack of information. I got my Fass with in less then a week of joining M1973M. That famous Blue Chip quote is bad, if you read between the lines like I do. Other forums said 5 PSI is when you start to worry about lift pump pressure. I thought every thing was fine with the OEM pump, truck ran just fine for 10 years. You know, sometimes when a company is no longer making the current model of a product, they will outsource the replacement parts and they become cheaper and less reliable. I just cant understand why the first VP44 lasted so long, with the OEM lift pumps?

[Mopar1973Man]

It was not about money, it was more a lack of information. I got my Fass with in less then a week of joining M1973M. That famous Blue Chip quote is bad, if you read between the lines like I do. Other forums said 5 PSI is when you start to worry about lift pump pressure. I thought every thing was fine with the OEM pump, truck ran just fine for 10 years. You know, sometimes when a company is no longer making the current model of a product, they will outsource the replacement parts and they become cheaper and less reliable. I just cant understand why the first VP44 lasted so long, with the OEM lift pumps?

Hit on the nail... The problem is that BlueChip had worded his comment on his web page poorly and the masses are soaking it up as the fact... :banghead:

I wasn't so lucky in the 2nd year of ownership of my truck the VP44 and lift pump both failed just before 50K miles...

[flman]

I just ordered the 1/2" hose kit at Vulcan, I think I am going to send this thread to Chip. He should really change that info, for people that read between the lines.

[FlatTwin]

Had good luck with Vulcan. Had a duff (leaking) pump at first and Raptor took care of it. Was a mess at first but now a few months on the fuel pressure (have the 1/2 lines) is rock solid and does not vary more than 2-3 psi. Sits on 17-18 psi at idle and never gets below 14 even when cold.

Edited January 28, 2010 by FlatTwin
Someone is proof reading my posts! :)

[Mopar1973Man]

...does not vary more than 23 psi.

I think you mean 2 to 3 PSI...

[AH64ID]

From everything I have read you want between 10 and 20 psi on a VP at all times... I wonder if people are starting to confuse CP3 psi's with VP's?? The CP3 just needs -5 - +15psi... Not a hard range to satisfy.

[Mopar1973Man]

From everything I have read you want between 10 and 20 psi on a VP at all times... I wonder if people are starting to confuse CP3 psi's with VP's?? The CP3 just needs -5 - +15psi... Not a hard range to satisfy.

Actually that's wrong too... (I hate to say it) I found several service manuals (Dodge FSM, AllData, Mitchell1) stating the CP3 minimum pressure is 9.5 PSI... You might want to look it up...http://mopar.mopar1973man.com/cummins/3rdgen/fuel-system/fuel-system.htm

[AH64ID]

Actually that's wrong too... (I hate to say it)

I found several service manuals (Dodge FSM, AllData, Mitchell1) stating the CP3 minimum pressure is 9.5 PSI... You might want to look it up...

http://mopar.mopar1973man.com/cummins/3rdgen/fuel-system/fuel-system.htm

I do believe that when the HPCR first came out the FSM had 9.5 in it. I have heard about the reference before. But its the general consensus it was a typo and carryover from VP psi requirements. Consider the in-tank lift pump is internally bypasses at 8psi, and that the dmax CP3 doesn't come from the factory with a lift pump, operates only on the CP3's suction pump, which is also on the Dodge CP3.

"The CP3 Inj Pump has a built-in gearotor-style lift pump, driven by the pump shaft - it will develop 20" vacuum at higher rpm, and is designed to pull fuel from the tank thru a filter."

I have searched and searched the 2005 and 2006 service manuals and there is no longer a reference to a minimum pressure.

Edited January 30, 2010 by AH64ID

[Mopar1973Man]

I do beleive that when the HPCR first came out the FSM had 9.5 in it. I have heard about the reference before. But its the general concensus it was a typo and carryover from VP psi requirements. Consider the in-tank lift pump is interally bypasses at 8psi, and that the dmax CP3 doesn't come from the factory with a lift pump, operates only on the CP3's suction pump, which is also on the Dodge CP3. "The CP3 Inj Pump has a built-in gearotor-style lift pump, driven by the pump shaft - it will develop 20" vacuum at higer rpm, and is designed to pull fuel from the tank thru a filter." I have searched and searched the 2005 and 2006 service manuals and there is no longer a reference to a minimum pressure.

I've noticed that too... But the funny part is most all service manual like AllData, Mitchell1, Dodge FSM seem to be short on information as they went forward in time from 2003... Strange but true... But still in all performance wise wouldn't it be still good to have positive pressure to the CP3? I know there is a overflow valve on the CP3 and there is a little information on it but not enough to know anything about specs... But wouldn't it be wise to setup you fuel system simuliar to the VP44 to be able to bare crack open the overflow vavle and have good fuel flow? (Now I'm on the learning curve...)

[AH64ID]

I've noticed that too... But the funny part is most all service manual like AllData, Mitchell1, Dodge FSM seem to be short on information as they went forward in time from 2003... Strange but true... But still in all performance wise wouldn't it be still good to have positive pressure to the CP3? I know there is a overflow valve on the CP3 and there is a little information on it but not enough to know anything about specs... But wouldn't it be wise to setup you fuel system simuliar to the VP44 to be able to bare crack open the overflow vavle and have good fuel flow? (Now I'm on the learning curve...)

It certainly does help, mainly from the standpoint that the CP3 doesn't have to work to get fuel.. thus you are not robbing hp. Dmax's see a decent hp increase when they add a LP. The 10-20 range seems to be plenty. There are guys running more, but it hasn't been a huge provider of extra hp. On my truck I run between 5-9 with the stock LP and 3 filters.. I am in no way worried about the pump or lack of hp. When my OE LP fails I will put a Raptor in the system and will keep idle pressure at 13-15. For a CP3 I reccommend 2psi as a minimum. Not becuase below that the CP3 is hurting, but becuase 99% of people have psi gauges, not psi/vacuum gauges and between 0-2psi the guage isn't as accurate at 2-20psi... Just my .02 Edited January 30, 2010 by AH64ID

[flman]

Chip emailed me back after he viewed this thread. I will only list the facts, if you want to email Chip, you should, because I will not share the entire email with you and his feelings.

"there is a .016 bypass hole in the regulator valve to guarantee return fuel and therefore cooling. This is why the pressure drops after you shut off the engine."

on the 5PSI dyno test

"that was then and now is now. "

I have been telling you all along, he does not recommend this, on the same page he is selling a Fass pump.

[Mopar1973Man]

LOL! OMG! That tiny hole... (Magnified x12) http://forum.mopar1973man.com/attachment.php?attachmentid=548&d=1265209366 http://forum.mopar1973man.com/attachment.php?attachmentid=547&d=1265209337 Now give you an idea how small that hole is he's talking about you can take a single straind of copper wire from a 16 AWG cable and it will barely pass. 14 AWG straind won't... Now figure out at 5 PSI how much fuel flows though that tiny hole. NOT MUCH! So how could this even be considered a good cooling flow? That bleed hole was design for priming the system and passing air. Air will pass through a small hole easy where fuel will slow down considerably. Now looking at the overflow hole at 14+ PSI now you pumping fuel and cooling... But that tiny hole... Sorry I'm going to hold to Dodge/Cummins/Bosch standards personally... Being that I lost my first pump at 8 PSI of fuel pressure. Then on top of that if you preform the volume testing of the lift pump according to the TSB if the lift pump volume test fails at 8 PSI... (Dodge/Cummins TSB) http://dodgeram.info/tsb/2003/14-002-03.htm As for my testing of 8 Psi I did it 10 times and all 10 times I came up short in the volume requirement at 8 PSI... (Pic attached) http://forum.mopar1973man.com/attachment.php?attachmentid=549&d=1265210510 As for dyno test and quarter mile testing of pumps... That short life testing... Still there is nothing from any re-build shop that can prove 100K, 200K or even 500K with 5 PSI of pressure... Remember we are common folk that drive long distances not race a quarter mile and load up on a trailer and go home. Like myself is 70-100 miles just to go grocery shopping... Or 100 miles for a load of firewood climbing a 7-10% for 15 miles... I need a pump to last a long time... I can careless about max HP/TQ at what fuel pressure... I've got difference requirements...

Edited February 3, 2010 by Mopar1973Man