fuel pressure info/test

[**ICEMAN**]

finally got around to installing my gauge in the 01. heres a couple results i got

the sensor is installed at the pump test port

electric WESTACH

stock banjo bolts



at idle-11psi

2500 rpms (in park)=9psi

driving normal with ez on=8-10psi

WOT with ez=5-7psi

ez & power max on level 5 at WOT=4-6psi

ez & power max on level 9 at WOT=0-1psi



i wasn't aware that the extra fueling from the boxes lowered the pressure. i must have skipped that part in my tdr surfing.



will drilling the bj bolts help these numbers??

 

[Bob Wagner]

yes it will

and purchase the modified banjo bolts from ray t.

 

[nps]

Think Geno's have the new banjo bolts in sets of 3, 4 or 5 regular and 2, 1, or 0 1/8 NPT for guages.

 

[**ICEMAN**]

bob,,any ballpark ideas of how much better the readings will be with the modified bj bolts?

 

[dresslered]

I think that your only hope of maintaining adequate pressures with a fueling box is by adding a pusher pump. The modified banjos will increase the flow but I doubt you will see any pressure increase.

 

[Steve St.Laurent]

Drilling out the banjo bolts will help slightly but not much - maybe a 1 psi improvement. Dresslered is right IMO - in order to keep your pressures up you'll have to either add a pusher pump in addition to your stock pump or replace the stock lift pump with an aftermarket pump back at the tank. Many of us are researching the different options out there on this, do some searches on "lift pump" and you'll have about a weeks worth of reading! I went with a pusher pump back at the tank in addition to the stock lift pump and I'm seeing 19 psi driving down the road and 18 psi at WOT - that's with a Powermax3 on level 9 and 275 injectors.

 

[**ICEMAN**]

thanks dave & steve for the info. i know one thing i already messed up on and its the gauge(0-15psi). if your seeing high teens then i need another gauge. i'm gonna drill the bj bolts to ray's specs and do the pusher pump deal. where do i get the pusher pump and how much?

thanks again

 

[dresslered]

Iceman-



I would not worry about the pressure gauge unless you're into serious performance. I too have the 15-psi gauge. Many of the pusher pumps (i. e. Carter) are adjustable so that you can keep the pressure within your gauge limits. I am still in the research phase so I can't help you out on which pump is best suited to your application. Like Steve says, do a search and you will be more confused than ever!



Just curious Steve, why do you have your pressure so high? Isn't this causing most of your fuel to return to the tank?

 

[Steve St.Laurent]

David - there's nothing on the pumps that I have that allows you to adjust the fuel pressure on them. The pusher pump is a low pressure (6-7 psi) high volume pump and the stock pump is just that - stock. Those are the pressures you get with that setup. I went with this setup because Enterprise researched it and have had it running on a number of trucks since January including hot shot rigs and haven't had any problems. I've been watching the fuel pressure thing for a LONG time and this was the solution I decided to try. BTW, according to testing that Mopar Muscle and Bill Kondolay have done they didn't see any increase in flow to the tank at higher pressures - which seems strange to me but that's what they saw.



You can get a pusher pump kit from Enterprise Engine Performance ( http://www.enterpriseengine.com ). I have a thread on the install that goes over everything at https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=19767&perpage=30&pagenumber=1 . So that you are making a fully informed choice you should know that EMDDIESEL put their pusher pump kit on his truck and has now bypassed it because of fears that the fuel pressures are too high - you can read his post at:

https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=22838



On the fuel pressure gauge I'm running a 0-16 psi Stewart Warner gauge that I have modified to read up to 20 psi - you can read about that at:

https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=19919



-Steve

 

[dresslered]

Thanks again, Steve. I read about your modified pressure gauge and I think that I would be more worried about damaging the diaphram of the sender from over pressure than sending too great of a voltage to the gauge. I think that the SW senders can take a little more pressure than the autometers.

 

[Steve St.Laurent]

I called Stewart Warner about the senders and talked to an engineer there. He said he didn't think there would be a problem with the senders at 20-22 psi but they hadn't tested it at that pressure. I wasn't worried about damaging the gauge with too high a voltage - I just wanted to be able to have it in scale so that I could see if I was having a pressure drop across the filter. Thus far I have 6,000 miles on the senders at the higher pressures with no problems.



-Steve

 

[Mopar-muscle]

i was going to stay out of this volley till i saw my name mentioned , yes its true that we increased pressure and saw no return in fuel flow back to the tank , there is a reason , not sure exactly what , but it has to do with the design of the VP44 .



ice , 2 things to modify , first are the banjos , and second is the banjo fittings between the lift pump and the fuel filter , you will pick up more flow and 2 psi .



you should move your pump back to the tank as your first test , won't cost much and if you decide to go the pusher pump route you already have the lines modified .



your numbers look good to me , except for your level 9 , how often do you use level 9 ? if not often you will get more than enough fuel with the banjo mods , but i would seriously just ditch the factory lines from the out put of the lift pump to the VP44 and modify the inlet to lift banjo .



i get 5 psi at WOT with my hot pe in level 3 , DD3's and EZ , this is doing triple digit speed , with a carter hp 15 psi pump in the stock location , stock power wiring and replacement lines from lift pump to the VP44 , also modified my fuel filter for increased flow . over 400 hp to the ground .

 

[csutton7]

food for thought---could the reason be why you/we don't see an increased flow rate back to the tank is the VP44 can't push/pump it any faster or because the 5/16" line can only flow so much---if this is the case then guys using these pusher pumps and aftermarket pumps are just pumping fuel to the VP44 and could most of it just be sitting there in the lines(if you will) causing the pumps to overwork themselves--I know some pumps are internally bypassed which would help--but I still think a regulator can't hurt if you've got a lot of pressure or are moving a lot of fuel... any ideas------chris

 

[Todd T]

Chris in MM's tests he showed more fuel being returned at lower rpms than at high rpm's.



the only thing, that would show is the pump is either using more. or as you said it doent have the ability to pump and/or have much pressure.



who wants to upgrade their return lines as an expirement?



MM what where your numbers on the return. did you look for pressure on he return? or just flow?



I know I know, I'm gonna get this going again but we all have had time to purge since the "Pumps, Lines and whatnot" debate

 

[csutton7]

Todd T---it's been awhile since MM posted his findings and I didn't go back to reread them(it'd take a week)--thanks for the update--and you're right we might get this thing pumped up again(he,he)



I didn't upgrade my return line from the VP44; I'm running a separate line off of a regulator back to the tank--the ol' R&D continues---I can burn pumps up faster than you'd like to know--sure would like to find "one" that works--maybe I'm running it now only time will tell----chris

 

[HVAC]

Why would we want to upgrade our return lines?

 

[Mopar-muscle]

yes that is correct , we had more flow back to the tank at lower rpm , and hifgher pressure . when i say we increased pressure , we went from nothing to a max of about 4 psi , this was with a stock lift pump . no we didn't check pressure in the line , as we found out pressure is a restriction to flow , we were concerned with the volume going back to the tank , as rpm increased , flow decreased , which means it was going in the cylinders , but we hit a wal and as the pressure at WOT increased , the flow did not , that leaves me ... and bill ... with the belief that the VP44 is the restriction and will only allow so much in thru its inlet orifice .



anywho , it would be interesting to increase the return line size , csutton has which is a by product of the JRE system he has ... or did you leave the return side stock chris ?



anyways interesting debate , agian . haven't had a chance to unplug my lift pump to see how long the truck will run , but i was ccycling the key on and off a number of times today and the pump sounds as strong as ever , i'll have the pressure gauge on it tomorrow .

 

[Mopar-muscle]

Originally posted by HVAC

Why would we want to upgrade our return lines?

because biggger is better oh sultan of soot ????

 

[csutton7]

MM--the JRE thing sits in the tank basically unused as I'm gravity fed-but the OEM return is still running thru it---



the only reason to upgrade the OEM return is if the ol' VP can be made to return more fuel and since this is upproven I think it best to add a return/regulator if you think you're pumping to much fuel..... chris

 

[**ICEMAN**]

Originally posted by Mopar-muscle

we hit a wal and as the pressure at WOT increased , the flow did not , that leaves me ... and bill ... with the belief that the VP44 is the restriction and will only allow so much in thru its inlet orifice .

you all are right,,the more i read about it the more confused i get. if the job of the overflow valve is to send any fuel higher than 14psi back to the tank then nothing we do before it gets to the valve will actually increase flow to the vp44. so to keep 14psi at the pump during heavy acceleration i need to have 25psi or so at the test port,at idle,(correct)?? which does mean the return lines need upgraded to return any fuel over 14psi back to the tank under light throttle. am i on base here or way off??help! does the overflow valve need bombed to send any press. higher than 20 or so psi. back to the tank?