Fuel Pump PSI
 

Idle psi?
55-60 psi?
what are they?

If your in a VP-44 equipped truck and ildling at these pressures, run she's gonna blow. What is it your wantin to know.

By fuel pump you mean Injection Pump and for a second generation truck it is:
15 to 18 PSI at idle.
no less than 13 under load and no less than 11 at WOT.

If you see anything less than that you need a new lift pump (transfer pump) or to at the very least change your filters. If you have many days of low pressure you will effect the health of your IP.

There are many options on this fix and many other items related to it.

Ok i have vp 44 but i get around 13 to 14 at idle new filter 2 weeks ago lift pump a year ago. I have an edge and if its turned up all the way and i get in it it will drop to 3-4. just wondering what the pressures were supposed to be

Sounds like its time for a FASS

3-4 psi at Wot aint good man.......you need to upgrade yer fuel delivery

A better lift pump, larger fuel lines, a better pickup system in the tank and replacing or modifying the banjo bolts are all way to improve the fuel flow and psi numbers.

Be sure to fill out your signature so we can see what you have, this helps answer questions better.

There are several aftermarket lift pump kits that can help you with the low fuel pressure problem.

FASS is one way, Walbro 392 kit (the way I went) is another, upgrading fuel lines is another, just going to 1/2" fuel line from Vulcan helped my stock pressures out a bit.

Do some reading and find the kit that makes the most sense to you.

I have just installed a belt drive lift pump that so far I am completely impressed with also.

Oh Cmon guys, What he really needs is a New Helix 2 Cam and a Manual pump setup!!!!

Just Kidding! These guys wont lead you wrong!

Here is the specs from Dodge FSM for the VP44 trucks...
http://mopar.mopar1973man.com/2002%2...20pump/FP2.jpg

I've stayed at this rule and never had a VP44 problem or failure... :yeah:

This is what I am running.

45 psi at idle, 43 at cruise, 37 at WOT. :c:

I have a Draw Straw, -8 lines on the suction side and -6 on the pressure side running through the factory filter housing. Yes, I still have heated fuel if needed.

Dave

WOW Dave..thats way too much pressure

I am suprised it runs at all

yer VP internal spillack is in full tilt

what the heck ya runnin fer a pump???

12 Valve lift pump. I am working on a custom bypass, post filter. That should limit presure to 25 or so psi.

I have over 60K on the current setup.

And don't forget, too much is almost enough!!


Dave

Did you get a MITUSA?

You must not have been running these pressures for very long now. Even 25 is still to high. Your gonna end up blowin the internal overflow or the diaphram on the pump if nothin else happens first. 21psi is the max that even Bosch says the pumps will tolerate on a regular basis, the rebuilder I taked to reccomends 18psi max even for competion trucks that they sponser.

We tried for the MITUSA, that's what I wanted but didn't have any luck gettin a hold of the vendor. He is a busy man.

If you want one I can get it for ya if you want to pay the price. I've have quick and easy access to Opie through Nathan Wright.

I am not sure if it will last. It's still doing fine with over 60K on the clock, approaching 70K on the next oil change.

I'll keep running it until it fails. This VP has already lasted longer than the factory unit running "spec'd" pressures. :D

Dave

MikeL was who we were trying to go through. As I understood it he is the only vendor for them. At this point I would say that this belt drive pump system is gonna be the only way to go once it catches on. This thing rocks. Hopefully when the next guy is ready to give it a shot you can help them out. I'm already up and runnin on it myself.

Which one are you using?

You'll never hear me tell anybody they are wrong for tryin somethin different. That's how we learn about these things. Just throwin the warnings out there to make sure you are informed about what your doing. It's hard to know from a few threads if somebody is a newby makin un-informed decisions or if your somebody that knows what's goin on and your just takin a different route. If you had been the newby I'd feel like we failed ya if we hadn't given the warnings, but since your not drive on and keep us up on any changes.

It's all good. I don't pretend to have any of the answers. And what works for me may not for others. Just the way it goes I guess.

Dave

I ended up with the look-a-like from Glacier Diesel. I needed something in a hurry cause my old electric pump was dead and i can't be without the truck.

I know guys that are running close to 100psi at WOT in the DMax and havent blown up a CP3 in over two years of racing, BUT...that doesnt mean there isnt some damage taking place that will show its ugly head later on. They are running modded CP3 though.
That 42psi idle pressure is just nuts. My LLY didnt like anything above 13psi or it would spit and sputter like a $2 whore on Bourbon St.

In a common rail/CP3 systems of the 3rd Gen Dodge trucks that would be closer to normal pressure but we don't generally run near this in the VP44 trucks.

Oh my mistake, I didnt realize you werent running a CR.

Yeah, we know, some of us are still stuck in the dark age's................:ph:

:c:

Happilly stuck in the dark ages, thank you.

I have a 99 with a fass fuel pump and 1/2 line going to the fuel filter and my pressure stays around 9 psi all the time, whether if its at idle or pulling, and i was just wondering if there is anything that i should do or not to worry about it. (ps. sometimes it does climb to 12-13 psi but not all the time.)

9 is at the bottom of the acceptable rangebut it is fine as long as it doesn't drop below that any time. I would however be concerned with why it fluctuates periodically. That could be a problem in the making.

MINIMUM FUEL PRESSURE 10 PSI...

Straight from the man MOPAR1973MAN. Thanks Michael. Good info.

Lift Pump Diagnostics
TSB 14-002-03
Diesel Transfer Pump Diagnosis
Overview:
Improved diagnostic procedures are available which will greatly improve identifying a faulty fuel transfer pump. The improved procedures test the 'flow" capability of the transfer pump. It sufficient fuel reaches the injection pump from the low-pressure system, then the cause of engine performance problem(s) lies elsewhere.

Specifications:



Equipment Required:


6977 Kit, Diesel Fuel Pressure (Includes 06628 Gauge and #8976 Fitting)
6631 Adapter, Fuel Pressure

Diagnostic Procedure:

The following procedure is to aid in evaluating the low-pressure fuel system performance in the absence of fault codes.

1. Inspect all fuel lines (including chassis) for kinks and leaks. Repair prior to proceeding.

2. Battery voltage must be greater than 11.5 volts. If not, charge batteries as required.

3. Remove the rubber fuel hose from the outlet side of the fuel filter (Fig, 1).

1 - TEST PORT FITTING
2 - VP-44 FUEL INLET LINE
3 - RUBBER FUEL HOSE
4 - FUEL FILTER OUTLET LINE
5 - HOSE CLAMPS (2)
6 - VP-44 INJECTION PUMP
Fig. 1 FUEL HOSE AT FUEL FILTER


4. Attach a 915 mm (36 in.) clear hose to the fuel filter outlet line (Fig. 1). Do not use the pressure test fitting.

5. Route the hose to a clean, empty 3.8 liter (1 gallon) approved diesel fuel container.

6. Purge all air from the lines by bumping the starter to activate the transfer pump (transfer pump should run for 26 seconds).

NOTE: THE TRANSFER PUMP WILL RUN LESS THAN 2 SECONDS (VARIES WITH ECU CALIBRATION) WHEN THE IGNITION KEY IS FIRST TURNED TO ON. WHEN THE STARTER IS BUMPED (DO NOT ALLOW THE ENGINE TO START), THE TRANSFER PUMP WILL RUN 25 SECONDS. IF THE ENGINE HAS BEEN RUNNING, THE IGNITION KEY MUST BE CYCLED TO ALLOW THE TRANSFER PUMP TO RUN.

7. If the transfer pump runs, proceed to step 8. If the transfer pump does not run, check electrical circuits as follows:

a. Verify 12 volts are present across the transfer pump connector Use test light to verity current flow.

b. If 12 volts are present - Measure the resistance across the transfer pump. If greater than 200 ohms or less than 0.2 ohms, replace transfer pump.

8. Empty the container of fuel.

9. Bump the starter to activate the transfer pump. Look for air bubbles. If no air bubbles are present, proceed to step 10. If bubbles are present, check the lines/connectors between the fuel tank and the transfer pump for conditions allowing air to be drawn into the fuel system. Correct the condition and repeat steps 6, 8, and 9.

10. Measure the amount of fuel in the container after the pump shuts off. If the amount of fuel in the container is GREATER than 1.33 liters (45 fluid ounces) and the fuel is bubble free, then the low-pressure fuel system is OK, the cause of engine performance problem lies elsewhere. No further testing of the low pressure fuel system Is required. If the amount of fuel in the container is LESS than 1.33 liters (45 fluid ounces), proceed to step 11.

11. Connect fuel pressure test gauge #6828, included In the #6i977 Diesel Fuel Pressure kit, to the pressure fitting located on the fuel filter inlet. If the vehicle is a 2002 model, install test fitting #6976, included In the #6977 Diesel Fuel Pressure kit.

12. Purge all air from the lines by bumping the starter to activate the transfer pump. Empty the container of fuel.

13. Bump the starter to activate the transfer pump for 25 seconds. Observe the hose for air bubbles. Record filter inlet pressure.

a. If fuel filter inlet pressure is greater than 34.8 kPa (5 psi), replace the filter element, and repeat step 12 & 13.

b. If bubbles are present, check the lines/connectors between the fuel tank and the transfer pump for conditions allowing air to be drawn into the fuel system. Correct the condition and repeat step 12 & 13.

c. If fuel inlet pressure is less than 34.8 kPa (5 psi), proceed to stop 14.

14. If the fuel quantity continues to be LESS than 1.33 liters (45 fluid ounces), connect a fuel vacuum test gauge #6828 using the fuel pressure test adapter #6631 between the transfer pump and the chassis mounted fuel lines.

15. Purge all air from the lines by bumping the starter to activate the transfer pump.

16. Empty the container of fuel.

17. Bump the starter to activate the transfer pump for 25 seconds. Observe the hose for air bubbles. Record transfer pump inlet vacuum.

a. If inlet vacuum is greater than 152.4 mm/Hg (6 in/Hg), excessive restriction exists between the tank and the transfer pump. Inspect/repair the chassis fuel lines and/or fuel tank module for kinks and/or restrictions. After correcting the restriction, repeat steps 15, 16, & 17.

b. If bubbles are present, check the lines/connectors between the fuel tank and the transfer pump for conditions allowing air to be drawn into the fuel system. Correct the condition and repeat step 15, 16, & 17.

c. If the fuel quantity continues to be LESS than 1.33 liters (45 fluid ounces) and no bubbles are present, replace the transfer pump.


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You might want to surf my site now and then... There is always something new posted up or new information...:w2:

But Thanks for the great comment! :U:

I do, and love reading your info as always. Glad to see you around man. :c:

problem found
 

Well after reading all of your replys, I looked into it a bit further and it turns out that the line for the gauge that goes from the isolator to the gauge was void of fluid which i read elseware that there is supposed to be some in there. After I put some new fluid in there according to the manufacures specs, it turns out that there is lots of pressure in my fuel line. So right now it is sitting at like 22 psi and not 9, and when under load it only drops down to about 18. So i hope that this was it and nothing else.

Sounds like you fixed your problem with an easy fix. :up:

This is one good reason why I never installed a ISOLATOR in my truck...
http://mopar.mopar1973man.com/2002-d...sure-parts.jpg

I've been setup this way for nearly 5 years and never had a problem. If a problem does happen not a problem. All I got to do is turn off the fuel to the gauge using my needle valve. But for you guys with isolators if it blows out (which does happen without warning) now you got ZERO ways of turning off the fuel...

Dr. Evil would agree...:w2:

Anyone in Canada and specifically in BC caught with a pressure gauge that does not have an isolator (oil, fuel etc.) will have their vehicle impounded with all repairs being made by a licenced mechanic at the owners cost.

Isolators can and do go nuts but they are easy to fix and frankly well worth it considering the alternatives. We used to install them on everything and I have one on my FP gauge. I have had it where you need to open it up and push down the diaphragm now and again and or refill it with 50/50 but like I said, owner choice.

Personally, not worth the trouble.