fuel pressure for 12V? - Competition Diesel.Com

gstanfield · 03-28-2007, 01:45 PM

I'm wanting to add more guages to my truck and thought I'd throw in a fuel pressure guage so I'd know when the overflow valve goes bad. What pressure is the 12V supposed to be running? Also, where would be a good place to feed a pressure guage off the P7100?

Thanks,
George

Ridemywideglide · 04-07-2007, 02:56 PM

I'm not completely sure what pressures are "normal".. I've been told 22 or so at idle and 17-18 at 2500 free-rev..

Mine however, runs about 38 at idle and will hold 42 at 75-80 mph..

Alot of guys tap the supply banjo bolt on the side of pump and put the line there.. I chose the easy route and removed the bleed plug on top of the filter housing and put my valve in there, then ran the line off that to the guage.. Let me know if you want some pics.. got the head off right now so should have a clear shot..

Brad

jambbii · 04-10-2007, 12:23 PM

I tapped the banjo bolt. It was cake.

quihi35004x4 · 05-07-2007, 10:57 AM

I have a tapped banjo...mine is running around 20 at idle and 18 at 70 mph

wildmanben · 05-07-2007, 11:15 PM

I got about 25 at idle and 8 at WOT...

GSM-01 · 05-08-2007, 12:21 AM

Well, the 8 seems extrememly low to me. I had a 887 truck that got to 9psi and we had bad rack float. I don't know if that is normal for that psi but it was a major problem as it was falling flat on its face over 2500 rpms. I have always been told 25 idle, 15 WOT are good number to go by.

RacinDuallie · 05-08-2007, 04:22 AM

Quote:

Originally Posted by wildmanben

I got about 25 at idle and 8 at WOT...

8 @ Wot is alittle on the scary side

wildmanben · 05-08-2007, 12:34 PM

yeah I know, Still trying to figure what to do about that....

DONK78 · 05-08-2007, 05:23 PM

Quote:

Originally Posted by wildmanben

yeah I know, Still trying to figure what to do about that....

Join the crowd, auxillary fuel pump though the mechanical pump is awesome at one point it just can't keep up.

oldsmokey97 · 05-08-2007, 05:25 PM

ok..... i checked my fuel pressure at the line coming out of the filter housing to the pump. and i had around 40 at idle and about 15 at WOT.

But, is there a pressure difference betweent the two different spots (side of pump and filter housing) ?
Cuz i am hearing people with 40 something psi and some people with 20 psi. Why is there soo much of a difference?

Lance

wildmanben · 05-08-2007, 05:38 PM

mine was on the banjo for the inlet of the pump.

oldsmokey97 · 05-08-2007, 10:36 PM

yah but why is your readings soo much different than mine?

lance

wildmanben · 05-09-2007, 12:10 AM

215 pump vs 180 pump? I dunno. Its got a new overflow valve too.

oldsmokey97 · 05-09-2007, 04:38 PM

the only different thing different that i have done to mine is stretch the spring in the overflow valve. Would that make the difference??

If not then what is the deal?

lance

wildmanben · 05-10-2007, 12:29 AM

stretching it will give you some more pressure but its only for a little bit. did it to a buddies truck and he saw 45 at idle.

Ridemywideglide · 05-10-2007, 01:06 AM

Quote:

Originally Posted by oldsmokey97

ok..... i checked my fuel pressure at the line coming out of the filter housing to the pump. and i had around 40 at idle and about 15 at WOT.

But, is there a pressure difference betweent the two different spots (side of pump and filter housing) ?
Cuz i am hearing people with 40 something psi and some people with 20 psi. Why is there soo much of a difference?

Lance

There shouldn't be any difference.. Pressure at the top of the filter housing will be the same as pressure at the banjo bolt..
WOT no matter what RPM mine would not go below 30.. We'll see if it's the same when it's back together, but it should be as nothing with the inlet fuel system has changed.
All from the mechanical LP on the block...

oldsmokey97 · 05-10-2007, 03:50 PM

then why is my fuel pressure so much greater than wildmanbens??

i guess the stretching of the spring did make that much of a difference.

Lance

Ridemywideglide · 05-10-2007, 04:56 PM

I would guess.. I stretched mine as well.. Maybe a bit more than I should of from the sounds of it, cause mine's higher than both of yours..

03-28-2007, 01:45 PM	#1
gstanfield Name: gstanfield Title: Are we there yet? Status: Not Here Join Date: Jun 2006 Location: Casper, WY Member`s Gallery Posts: 777	fuel pressure for 12V? I'm wanting to add more guages to my truck and thought I'd throw in a fuel pressure guage so I'd know when the overflow valve goes bad. What pressure is the 12V supposed to be running? Also, where would be a good place to feed a pressure guage off the P7100? Thanks, George __________________ 1997 2500 SLT 4x4 #100 fuel plate, 16.5degrees timing, 3k GSK, Amsoil homemmade intake, Dodgezilla turbo, KDP killed, Dunrite converter & VB, 285/75R16's and autometer gauges.

04-10-2007, 12:23 PM	#3
jambbii Name: jambbii Title: milk Status: Not Here Join Date: Aug 2006 Location: Hot hot AZ Member`s Gallery Posts: 456	I tapped the banjo bolt. It was cake. __________________ 1960 Town wagon 4x4 P Pump 24v 06 Mega Cab 2wd Drw 70 challenger 04.5 QC 4x4

05-07-2007, 10:57 AM	#4
quihi35004x4 Name: quihi35004x4 Title: Rookie Status: Not Here Join Date: May 2007 Member`s Gallery Posts: 11	I have a tapped banjo...mine is running around 20 at idle and 18 at 70 mph __________________ n/a

05-07-2007, 11:15 PM	#5
wildmanben Name: wildmanben Title: Farmboy... Status: Not Here Join Date: Aug 2006 Location: South Dakota Member`s Gallery Posts: 884	I got about 25 at idle and 8 at WOT... __________________ 98 2500 QC SB 12v 5sp Country Performance Diesel PureFlow Technologies Southbend Clutch Bullseye Power JL Machine Fluidampr

05-08-2007, 12:21 AM	#6
GSM-01 Name: GSM-01 Title: Can turn wrenches Status: Not Here Join Date: Apr 2007 Location: On a drilling rig somewhere in the country. Member`s Gallery Posts: 1,481	Well, the 8 seems extrememly low to me. I had a 887 truck that got to 9psi and we had bad rack float. I don't know if that is normal for that psi but it was a major problem as it was falling flat on its face over 2500 rpms. I have always been told 25 idle, 15 WOT are good number to go by. __________________ 2015 Ram 3500 SRW CCLB Laramie Limited

04-07-2007, 02:56 PM	#2
Ridemywideglide Name: Ridemywideglide Title: Diesel NON-Pro Status: Not Here Join Date: Aug 2006 Location: Montrose, Colorado Member`s Gallery Posts: 369	I'm not completely sure what pressures are "normal".. I've been told 22 or so at idle and 17-18 at 2500 free-rev.. Mine however, runs about 38 at idle and will hold 42 at 75-80 mph.. Alot of guys tap the supply banjo bolt on the side of pump and put the line there.. I chose the easy route and removed the bleed plug on top of the filter housing and put my valve in there, then ran the line off that to the guage.. Let me know if you want some pics.. got the head off right now so should have a clear shot.. Brad

05-08-2007, 12:34 PM	#8
wildmanben Name: wildmanben Title: Farmboy... Status: Not Here Join Date: Aug 2006 Location: South Dakota Member`s Gallery Posts: 884	yeah I know, Still trying to figure what to do about that.... __________________ 98 2500 QC SB 12v 5sp Country Performance Diesel PureFlow Technologies Southbend Clutch Bullseye Power JL Machine Fluidampr

05-08-2007, 05:25 PM	#10
oldsmokey97 Name: oldsmokey97 Title: Too Much Time Status: Not Here Join Date: Aug 2006 Member`s Gallery Posts: 744	ok..... i checked my fuel pressure at the line coming out of the filter housing to the pump. and i had around 40 at idle and about 15 at WOT. But, is there a pressure difference betweent the two different spots (side of pump and filter housing) ? Cuz i am hearing people with 40 something psi and some people with 20 psi. Why is there soo much of a difference? Lance __________________ COMPETITIONDIESEL.COM Bringing the BEST Together

05-08-2007, 05:38 PM	#11
wildmanben Name: wildmanben Title: Farmboy... Status: Not Here Join Date: Aug 2006 Location: South Dakota Member`s Gallery Posts: 884	mine was on the banjo for the inlet of the pump. __________________ 98 2500 QC SB 12v 5sp Country Performance Diesel PureFlow Technologies Southbend Clutch Bullseye Power JL Machine Fluidampr

05-08-2007, 10:36 PM	#12
oldsmokey97 Name: oldsmokey97 Title: Too Much Time Status: Not Here Join Date: Aug 2006 Member`s Gallery Posts: 744	yah but why is your readings soo much different than mine? lance __________________ COMPETITIONDIESEL.COM Bringing the BEST Together

05-09-2007, 12:10 AM	#13
wildmanben Name: wildmanben Title: Farmboy... Status: Not Here Join Date: Aug 2006 Location: South Dakota Member`s Gallery Posts: 884	215 pump vs 180 pump? I dunno. Its got a new overflow valve too. __________________ 98 2500 QC SB 12v 5sp Country Performance Diesel PureFlow Technologies Southbend Clutch Bullseye Power JL Machine Fluidampr

05-09-2007, 04:38 PM	#14
oldsmokey97 Name: oldsmokey97 Title: Too Much Time Status: Not Here Join Date: Aug 2006 Member`s Gallery Posts: 744	the only different thing different that i have done to mine is stretch the spring in the overflow valve. Would that make the difference?? If not then what is the deal? lance __________________ COMPETITIONDIESEL.COM Bringing the BEST Together

05-10-2007, 12:29 AM	#15
wildmanben Name: wildmanben Title: Farmboy... Status: Not Here Join Date: Aug 2006 Location: South Dakota Member`s Gallery Posts: 884	stretching it will give you some more pressure but its only for a little bit. did it to a buddies truck and he saw 45 at idle. __________________ 98 2500 QC SB 12v 5sp Country Performance Diesel PureFlow Technologies Southbend Clutch Bullseye Power JL Machine Fluidampr

05-10-2007, 03:50 PM	#17
oldsmokey97 Name: oldsmokey97 Title: Too Much Time Status: Not Here Join Date: Aug 2006 Member`s Gallery Posts: 744	then why is my fuel pressure so much greater than wildmanbens?? i guess the stretching of the spring did make that much of a difference. Lance __________________ COMPETITIONDIESEL.COM Bringing the BEST Together

05-10-2007, 04:56 PM	#18
Ridemywideglide Name: Ridemywideglide Title: Diesel NON-Pro Status: Not Here Join Date: Aug 2006 Location: Montrose, Colorado Member`s Gallery Posts: 369	I would guess.. I stretched mine as well.. Maybe a bit more than I should of from the sounds of it, cause mine's higher than both of yours.. __________________ 1996 2500 CTD, Ext Cab SLT 4x4, 5 spd, 3:55's, 285/75/16's, Ultralite EGT, Boost & Fuel Pressure guages. Moded AFC, 191 DV's, Marine Cam, 5x012's, HX35, BHAF.