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#1 |
chevy truck fan
Join Date: Mar 2005
Location: Gilbert, arizona 85298
Posts: 1,991
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Low fuel pressure
i have a '86 C10 with dual tanks. i have a 5.3 GEN IV ('11 sub) for some reason I am averaging 53PSI at the rail. i have a AC DELCO EP380 fuel pumps. with the "Corvette style" regulator any ideas what could be causing low pressure. both tanks work - feeding fuel 7 there are no leaks.
thanks!! |
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#2 |
Registered User
Join Date: Jun 2015
Location: Carlos MN
Posts: 2,056
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Re: Low fuel pressure
Does it run all right? I may be all wet but 53 psi should be fine. Not a gen 4 but the gen 3 LS6 in my 98 Wrangler runs great at 55 psi. I'm running a Walbro 255 in-tank pump.
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#3 | |
BMW & ASE Master Certified
Join Date: Feb 2004
Location: Houston, Texas
Posts: 1,263
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Re: Low fuel pressure
Quote:
spec shows KOEO 55-61 PSI I had a WIX brand fail within months, full fuel pump pressure at the rail.... toss it and machined down a bosch fuel fuel regulator and installed it to the stock BMW fuel filter (this was a BMW to LS swap) https://www.bimmerforums.com/forum/s...sure+regulator also get wayyyyy more filter media in there. only down side is inlet and outlet ports are 5/16 in all of my gen5 swaps, I use a Bosch adjustable fuel pressure regulator and a -6an regulator holder/adapter. dial it in exactly what I need. clint
__________________
1987 Silverado - L83 5.3 w/ 6L80e ,A/C,P/W,P/L,TILT, HID projectors, Wilwood C-10 Pro Spindles w/ 2018 silverado front brakes & C-5 Corvette Rear Disc Brakes 1999 BMW 528i - 5.7 LS1 w/ 4l60e, Ford 8.8 IRS w31 spline posi & FX-r projector retrofit New project: 2006 BMW x5 6cyl AWD to L83 6l80e 4wd to 2WD / RWD A poor man buy's it twice finally got my domain name back, 87chevy.com.... site rework in progress |
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#4 |
chevy truck fan
Join Date: Mar 2005
Location: Gilbert, arizona 85298
Posts: 1,991
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Re: Low fuel pressure
thanks for the replies... the fuel press. gauge is reading 58 at idles and low rev driving. it "drops" to around 51-53 at hi revving instances. it runs really smooth and good in general.
clint: what does KOEO mean? thanks for your knowledge. |
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#5 |
Moderator
![]() Join Date: Jun 2017
Location: Cherryville, NC
Posts: 2,193
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Re: Low fuel pressure
KOEO Key On Engine Off
KOER Key On Engine Running ![]() ![]() ![]()
__________________
Family and country before all others... 2006 Chevy Silverado (Daily Driver) 2012 Chevy Equinox ![]() ![]() ![]() |
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#6 |
chevy truck fan
Join Date: Mar 2005
Location: Gilbert, arizona 85298
Posts: 1,991
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Re: Low fuel pressure
aussie, thanks for the reply.
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#7 |
Senior Member
![]() Join Date: Sep 2005
Location: Lewisville, Nc
Posts: 10,234
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Re: Low fuel pressure
i run the ac delco ep381 pump in mine
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David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube |
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#8 |
chevy truck fan
Join Date: Mar 2005
Location: Gilbert, arizona 85298
Posts: 1,991
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Re: Low fuel pressure
truckdude, i don't think it is related to the pump "type" as maybe a bad pump from the get go?? still not sure what is causing the "weak" pressure.... I feel 3 possibilities:
1) the corvette regulator/filter (just being set on the weak side) 2) 1 of the fuel pumps (dual tanks) 3) something up with the tank selector valve (not switching tanks completely) all items are new & purchased from normal channels (amz, lmc, rockaauto) just have to tackle 1 /time ... i guess ...just frustrating.. aarrggg |
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#9 |
BMW & ASE Master Certified
Join Date: Feb 2004
Location: Houston, Texas
Posts: 1,263
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Re: Low fuel pressure
I haven't done this myself yet, I've been putting this off for years, but when I get around to installing the passenger fuel tank I will set it up as a transfer pump, use the OEM switch, connector and new aftermarket selector valve, but will have that setup only as a transfer pump to the main tank. I would not trust the selector valve to operate at the higher pressures than intended...
with my setup, I might do one of 2 things.. 1) run the aux tank to the valve in, valve out would go to the vent port on the main tank... and then when off, the valve would switch and then the vent line would be connected to charcoal canister, any fuel left in the line should drain back down past the roll over valve .. main and aux tank would need a Y fitting on the charcoal line so the tank does not build pressure. 2) Use the selector valve again to retain the fuel level sensor / gauge working and just have the aux tank pump the fuel into a new bung / -an bulkhead fitting .. clint
__________________
1987 Silverado - L83 5.3 w/ 6L80e ,A/C,P/W,P/L,TILT, HID projectors, Wilwood C-10 Pro Spindles w/ 2018 silverado front brakes & C-5 Corvette Rear Disc Brakes 1999 BMW 528i - 5.7 LS1 w/ 4l60e, Ford 8.8 IRS w31 spline posi & FX-r projector retrofit New project: 2006 BMW x5 6cyl AWD to L83 6l80e 4wd to 2WD / RWD A poor man buy's it twice finally got my domain name back, 87chevy.com.... site rework in progress |
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#10 |
chevy truck fan
Join Date: Mar 2005
Location: Gilbert, arizona 85298
Posts: 1,991
|
Re: Low fuel pressure
clint, thanks for the info. I am in the process of having the injectors cleaned/tested/checked to see if that helps the hi end "lean" condition the tuner told me about. I liked the idea of the dual tanks, but it makes it harder and more expensive to work with...
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