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#1 |
Registered User
Join Date: Jul 2017
Location: Morgantown, IN
Posts: 3
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Stock C10 tank w/ efi
I installed a '94 LT1 EFI 350 into my '71 shortbed. I'm using the stock behind the seat fuel tank w/eec. I'm running and external FI pump. I've plumbed the pressure side from the stock (single line) sending unit, and the low pressure return through the passenger side/top tank tube. I'm wondering if my vented gas cap is "breathing" enough. Sometimes the truck will rpm surge & sometimes even die, making me wonder if it's vapor locking.
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#2 |
Registered User
![]() Join Date: Jan 2016
Location: Sugar Hill GA
Posts: 369
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Re: Stock C10 tank w/ efi
I have a LT1 in my 280z. How much pressure are you getting at the engine? It should be 40-43 psi. Plus is the pump close to the tank. electric pumps don't pull well, they are designed to push. How big is your input line to the engine? It should be 3/8 with the return no smaller than 5/16.
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1967 C10 Step side 1970 AMX 390 1977 Datsun 280Z highly modified with '95 LT1 power |
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#3 |
Registered User
Join Date: Jul 2017
Location: Morgantown, IN
Posts: 3
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Re: Stock C10 tank w/ efi
I mounted the pump down on the frame rail (under the dvrs door). Gauge at the fuel rail reads 42 lbs.
Pressure side into engine is 3/8" & fuel return is 5/16". The surging is very sporadic, as well as the dying. Most of the time it runs perfect. |
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#4 | |
Old member
Join Date: Jan 2002
Location: Liberty, & Garden City S.C. , U.S.
Posts: 19,940
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1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 ![]() Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs. |
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#5 |
Registered User
Join Date: Jan 2003
Location: Safford,AZ
Posts: 3,612
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Re: Stock C10 tank w/ efi
When it surges can you remove the gas cap while running and it "fixes" the problem?
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#6 |
Registered User
Join Date: Jul 2017
Location: Morgantown, IN
Posts: 3
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Re: Stock C10 tank w/ efi
It does it so infrequently, it's hard to pin it down. Yesterday it did it parked/running perfectly still in the driveway. I wished I'd thought quick enough to remove the gas cap then to see if it recovers.
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#7 |
Senior Member
![]() Join Date: Jun 2017
Location: burlington north carolina
Posts: 1,030
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Re: Stock C10 tank w/ efi
I went through all this on a rear mounted tank. the fuel pump needs to be as close to the tank as you can get it the tank does need to be vented outside of the cab and have a good return line. you can get sending units with two lines
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Tags |
efi, fuel, injection, tank, vented |
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