Engine/Transmission (1998.5 - 2002) Fuel Pressure numbers

[JCyrbok]

Put the Dakota Digital FP gauge in this weekend and now I'm curious as to what "normal" pressure numbers should be. I know this is posted probably 1000 times on the site but for the life of me I could not find it today. Here's what I'm getting for numbers.



Idle 12. 4-13. 4, usually 12. 8 though.

Cruising at 50mph is about 10. 4

Hard acceleration (wot) dropps to anywhere between 6. 00 and 8. 00 and starts to come back up at about 70MPH.



I also ran hard on the Highway and was pulling about 9-10psi at 90MPH



What are the Normal numbers for Idle, WOT and Cruising.



I realize that there may still be some air in the sender line which is causing the numbers but have read alot of other posts where people are running 14-15 psi at idle so I'm a tad concerned.



The Gauge works excellant and my pressures are steady and dont jump around.



It also looks pretty cool in the useless are that the "storage" cubby use to take up.



ANy comments or info would, as always be greatly appreciated



Thanks

J-

 

[Snow man]

J,your pump is starting to get weak,but still defintely working. id carry a spare,or just watch it,it if drops any more,id get it changed,I drove mine with a weak pump for over 15K miles,it wasnt dead,but always had positive pressure.

 

[dieselshu]

Fuel pressure

J, I just recently installed mine as well, and I am reading similiar pressures. I am going to look at installing the Enterprise engineering pusher pump kit. The webmaster Steve, installed one and had some great results. I wonder why a recall hasnt been issued on these pumps if there are so many failures

 

[JCyrbok]

pusher pump

my only concern with the pusher pump is that if the pusher goes out will the stock lift pump have enough power to pull the fuel thru the push and not kill the VP on the way home? Any thoughts?



J-



ps I think that DC finds it currently more cost effective to simply keep replacing the bad pumps than it would be to do a full recall like they should. just my . 02

 

[Bigsaint]

JC, assuming they are post FF,those numbers are fine. As long as it doesn't drop much lower under WOT or you start to see erradic bounces at idle or under throttle you have more than enough psi's IMHO. I think DC is calling for nothing less than 8 psi's at WOT now, but I wouldn't sweat 6, just keep an eye on it.



I agree with you on the pusher pump set up as well. While they seem to work out fairly well, if one goes I'm not sure you could limp home with the restriction.



Another option, to open the restriction, is to replace the banjo bolts at the outlet of the FF and the inlet of the VP44 with Weber fittings, a short length of braided SS line and Aeroquip elbows. You might want to consider this if you add a fueling box later.



Oh yeah. . we need pics !!!!



Scott W.

 

[andrewkoperdak]

make sure you have all the air out of your line. I have a new pump with about 10K on it. I get more than 15 at idle and WOT it is 11-13 psi. I never get less than 11 psi anymore.

My old pump used to drop pretty close to zero WOT.

 

[JCyrbok]

mpre pusher pump concerns and pressure numbers

Had a chance this morning to do some more driving and took a pen and paper with me to jot down numbers. This is what I got:



Start (cold truck) 11psi then climbed to 12. 2 after aprox 60secs.



11. 2 @ 25 MPH



10 @ 50 MPH



9. 4 @ 75MPH on highway and at operating temp.



7. 0 acclerating from 75mph to 85mph to pass a truck.



6. 4 from aprox 30mph to WOT up to 65MPH ( let off as that low number worried me)



Cold Idle was 12. 4

Warm idle after about 15 miles on highway at average 75 MPH

was 13. 2-13. 4psi



These are all post Fuel Filter with a filter that has about 6k on it. Never anything odd in the drain water/fuel when i drain which is about once a month. Never had WIF light come on. Never had bad load of fuel to the best of my knowledge and I run Standyne Performance in every tank. I'm gonna change out the filter to see what that does.



I have a couple of questions about the pusher pumps. 1) IF I go to a pusher would it be smart to also put in a new lift pump with the numbers I'm getting?



2) What happenes if the pusher or the lift pump were to fail will the other have enough power to get me home without killing the VP even with the restitance of the other dead pump in the way?



3) Are there any other after market lift pumps to replace the stock one that has more reliabilty?



Any comments will definately be appreciated.



Thanks

J-

 

[Snow man]

J,you dont need to worry about the 6 psi reading,any positive pressure at wide open is fine. I ran around for a yr with only 6-8 on the highway,and sucked it to zero with the comp on,as long as i kept it out of a vacuum i wasnt worried about it. If you are staying stock,dont bother with a pusher,you dont need it. If you really want to,just move the ilft pump to the rear in front of the fuel tank,run a new 3/8"line from the new pump to the inlet of the fuel filter ,use rays banjo bolts on the fuel filter,and VP44 inlet. Open up the elbow going into the fuel filter housing with a drill bit,and you'll have great pressure. I dont think there is a more reliable pump than the stocker as of now,especially if you move it rearward,it has to suck less,should make it live longer,and is easier to change there. So you know i have a new factory lift pump,and the enterprise pusher pump,i see upwards of 30psi fuel pressure,and once its hot it has 31-33psi at idle. I dont think you need this much pressure with a stock engine.

 

[JCyrbok]

fuel pressure

Cool thanks for all of your input, it really has put my mind at ease. I plan on having my truck until the wheels fall off ( and cant be fixed anymore. ) I was advised my my wife that this is the last Toy for a while so I did it right and went with Cummins. She only had 13 miles on her when i drove off the lot ( the truck not wife). ANd now I have my first child due in 1 1/2 months so I'm REAL interested in reliability for my truck in the long run. Thanks for everyones input



And hopefully I can help out int he future.



Thanks

J-

 

[RADdodge]

I’d agree that any positive pressure from the lift pump will be ok from the injection pump’s point of view, but if you have a warrantee intact, you might want to see if the dealer would replace it for you. Also, as far as pusher pumps are concerned, if you’re going to do it, do it right. Install a filter before the pump and a check valve in the line so if the pump does die (or you want to turn it off for some reason or other) your lift pump can still suck fuel from the tank. It probably won’t happen with a dead pump and no check valve. Lots of posts on this subject. If you want to see a pusher pump with a filter and check valve, check out the Truck Pictures below.



- Bruce