fuel pressure fyi - Competition Diesel.Com

B18B1LS1 · 12-02-2007, 06:05 PM

Found this interesting, when I installed my Aeromotive fuel pressure regulator I used the gauge port on the regulator to hook up my fuel pressure gauge. I had it set to 40 psi at idle, which gave me about 42 psi at 2000 rpms cruising, and around 32 psi at WOT. Today I moved the gauge back to my tapped banjo bolt on the pump inlet and found the readings to be different. Idle was the same but at a 2000 rpm cruise I was seeing nearly 60 psi! I set the idle down to 30 psi, and this gave me 40 psi at 2000 rpms and 30 psi on a long WOT run above 3000 rpms. Not sure if any of this actually affects performance but surely I don't need 60+ psi cruising down the highway.

97' CTD · 12-02-2007, 07:33 PM

I have my gauge set off the regulator too at 40 Psi??????????
Brandon

smokinrod · 12-02-2007, 08:07 PM

did ya have the boost reference hooked up ?that would boost the fuel pressure at drivin speeds

B18B1LS1 · 12-02-2007, 09:10 PM

Nope, no boost reference hooked up.

B18B1LS1 · 12-02-2007, 09:16 PM

Quote:

Originally Posted by 97' CTD

I have my gauge set off the regulator too at 40 Psi??????????
Brandon

how much pressure do you gain at 2000 rpms cruising compared to idle?

97' CTD · 12-03-2007, 06:43 AM

Cruising I dont know my gauge stays under the hood I dont have a in cab read out? My boost port isnt hooked up also?
Brandon

B18B1LS1 · 12-03-2007, 03:23 PM

Gotcha. Anyone know if the pressures from the inlet/return of a p-pump are supposed to be different or if its just the regulator? I have no idea what the fuel is doing inside that little guy so I'm interested in others results?

joeservo · 12-03-2007, 07:56 PM

how did you setup the regulator? in a p-pump, it needs to be
1, in the return line or
2,in front of it and remove the return from the pump (using the return from the regulator).

if you look at their instructions, use the carb setup if you do not use the return from the p-pump. use the efi setup if you use the return in the pump.

B18B1LS1 · 12-03-2007, 08:53 PM

I eliminated the overflow valve, ran a new line from the pump to the regualtor, ran from the regulator back to the tank. Is this what your asking/saying? You kind of confused me! Its just like any other efi setup I have done.

TxDiesel007 · 12-03-2007, 09:18 PM

Quote:

Originally Posted by B18B1LS1

how much pressure do you gain at 2000 rpms cruising compared to idle?

FWIW

i have my fp gauge in the cab, setup with a needle valve for a snubber. FP varies with temperature and viscosity of fuel so i see anywhere from 36-40 psi at idle, all i have done is tweak the OFV with some minor mods, IE an extra spring and stretch it, and the stock one...

I dont have a regulator in place of the OFV, i wish that I did, but if i do add more fuel to the truck or a FASS system or custom fuel system (doubt it, 600 horses and this thing is done, and im 50 away.) id go that route. I do have the needle valve plumbed into the banjo bolt tho.. and it has some permatex.. no leaks in the cab, no leaks at the pump either...

FOr the curious, go to dieseltruckresource.com, and look under the same username, i have pics of my setup there.. and a few others...

At idle i see once again 36-40 psi
At cruising speed, I usually see 40-42 psi
and at WOT my pressure drops to 22-26 psi....

The twins clean up the fuel pretty good, even these 150 horse dragonflies....

Ill try and get pics up soon enough...

Rick

B18B1LS1 · 12-04-2007, 03:34 PM

Those numbers sound more like mine when using the regulator port, interesting. Using the inlet banjo readings I gain a solid 10 psi over idle at 2000 rpms. I'm just gonna play around until I find the place that gives me the best mpg and call it good. I can't feel a performance difference from 10 psi all the way over 60 psi according to the butt dyno.

joeservo · 12-04-2007, 09:59 PM

Quote:

Originally Posted by B18B1LS1

I eliminated the overflow valve, ran a new line from the pump to the regualtor, ran from the regulator back to the tank. Is this what your asking/saying? You kind of confused me! Its just like any other efi setup I have done.

sounds right. just trying to give info to someone starting a new project.

Jim Fulmer · 12-04-2007, 10:41 PM

Quote:

Originally Posted by B18B1LS1

Those numbers sound more like mine when using the regulator port, interesting. Using the inlet banjo readings I gain a solid 10 psi over idle at 2000 rpms. I'm just gonna play around until I find the place that gives me the best mpg and call it good. I can't feel a performance difference from 10 psi all the way over 60 psi according to the butt dyno.

On the dyno, back to back runs at 50 then 100 psi fuel pressure at WOT.....HP net was zero! If I can maintain 40-50 psi at WOT on the road that is good for me.

Jim

12-02-2007, 06:05 PM	#1
B18B1LS1 Name: B18B1LS1 Title: Too Much Time Status: Not Here Join Date: Aug 2006 Location: L-ville, Ga Member`s Gallery Posts: 1,429	fuel pressure fyi Found this interesting, when I installed my Aeromotive fuel pressure regulator I used the gauge port on the regulator to hook up my fuel pressure gauge. I had it set to 40 psi at idle, which gave me about 42 psi at 2000 rpms cruising, and around 32 psi at WOT. Today I moved the gauge back to my tapped banjo bolt on the pump inlet and found the readings to be different. Idle was the same but at a 2000 rpm cruise I was seeing nearly 60 psi! I set the idle down to 30 psi, and this gave me 40 psi at 2000 rpms and 30 psi on a long WOT run above 3000 rpms. Not sure if any of this actually affects performance but surely I don't need 60+ psi cruising down the highway. __________________ '97 2500 ECLB 4x4 -- couple of turbos mixed with some random billet stuff and still slow '03 2500 QCLB 4x4 -- work truck '98 Camaro Z28 -- s475 and 10.50@130 so far... '92 Wrangler -- lifted locked and stretched

12-02-2007, 07:33 PM	#2
97' CTD Name: 97' CTD Title: FeFiFo-FoFeFeFi Status: Not Here Join Date: Jun 2007 Location: SW Central, OH Member`s Gallery Posts: 4,301	I have my gauge set off the regulator too at 40 Psi?????????? Brandon __________________ 1986 Fummins on 40's

12-02-2007, 08:07 PM	#3
smokinrod Name: smokinrod Title: diesel jerk Status: Not Here Join Date: Aug 2006 Location: allendale, michigan Member`s Gallery Posts: 1,232	did ya have the boost reference hooked up ?that would boost the fuel pressure at drivin speeds __________________ just another pewter dmax work stock puller

12-02-2007, 09:10 PM	#4
B18B1LS1 Name: B18B1LS1 Title: Too Much Time Status: Not Here Join Date: Aug 2006 Location: L-ville, Ga Member`s Gallery Posts: 1,429	Nope, no boost reference hooked up. __________________ '97 2500 ECLB 4x4 -- couple of turbos mixed with some random billet stuff and still slow '03 2500 QCLB 4x4 -- work truck '98 Camaro Z28 -- s475 and 10.50@130 so far... '92 Wrangler -- lifted locked and stretched

12-03-2007, 06:43 AM	#6
97' CTD Name: 97' CTD Title: FeFiFo-FoFeFeFi Status: Not Here Join Date: Jun 2007 Location: SW Central, OH Member`s Gallery Posts: 4,301	Cruising I dont know my gauge stays under the hood I dont have a in cab read out? My boost port isnt hooked up also? Brandon __________________ 1986 Fummins on 40's

12-03-2007, 03:23 PM	#7
B18B1LS1 Name: B18B1LS1 Title: Too Much Time Status: Not Here Join Date: Aug 2006 Location: L-ville, Ga Member`s Gallery Posts: 1,429	Gotcha. Anyone know if the pressures from the inlet/return of a p-pump are supposed to be different or if its just the regulator? I have no idea what the fuel is doing inside that little guy so I'm interested in others results? __________________ '97 2500 ECLB 4x4 -- couple of turbos mixed with some random billet stuff and still slow '03 2500 QCLB 4x4 -- work truck '98 Camaro Z28 -- s475 and 10.50@130 so far... '92 Wrangler -- lifted locked and stretched

12-03-2007, 07:56 PM	#8
joeservo Name: joeservo Title: Diesel Enthusiast Status: Not Here Join Date: Apr 2006 Member`s Gallery Posts: 235	how did you setup the regulator? in a p-pump, it needs to be 1, in the return line or 2,in front of it and remove the return from the pump (using the return from the regulator). if you look at their instructions, use the carb setup if you do not use the return from the p-pump. use the efi setup if you use the return in the pump.

12-03-2007, 08:53 PM	#9
B18B1LS1 Name: B18B1LS1 Title: Too Much Time Status: Not Here Join Date: Aug 2006 Location: L-ville, Ga Member`s Gallery Posts: 1,429	I eliminated the overflow valve, ran a new line from the pump to the regualtor, ran from the regulator back to the tank. Is this what your asking/saying? You kind of confused me! Its just like any other efi setup I have done. __________________ '97 2500 ECLB 4x4 -- couple of turbos mixed with some random billet stuff and still slow '03 2500 QCLB 4x4 -- work truck '98 Camaro Z28 -- s475 and 10.50@130 so far... '92 Wrangler -- lifted locked and stretched

12-04-2007, 03:34 PM	#11
B18B1LS1 Name: B18B1LS1 Title: Too Much Time Status: Not Here Join Date: Aug 2006 Location: L-ville, Ga Member`s Gallery Posts: 1,429	Those numbers sound more like mine when using the regulator port, interesting. Using the inlet banjo readings I gain a solid 10 psi over idle at 2000 rpms. I'm just gonna play around until I find the place that gives me the best mpg and call it good. I can't feel a performance difference from 10 psi all the way over 60 psi according to the butt dyno. __________________ '97 2500 ECLB 4x4 -- couple of turbos mixed with some random billet stuff and still slow '03 2500 QCLB 4x4 -- work truck '98 Camaro Z28 -- s475 and 10.50@130 so far... '92 Wrangler -- lifted locked and stretched