Author Topic: Elec fuel pumps  (Read 17793 times)

Offline HAULIN IT

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Re: Elec fuel pumps
« Reply #15 on: April 17, 2009, 01:24:14 pm »
Ok, I hadn't noticed you were the "Flat cam lobe kid" :D Here is my interest in the reason...Could the "Bad fuel pump, cam lobe, ect." have been mis- diagnosed for the very same problem you are having? Where did you have you rigged can installed? Before the switching valve, After, right before the fuel pump, just out of the tank? I feel you should get on the hose comming out of a tank & put your pump on there (by-pass all of the Two tank switching crap with a section of rubber hose) & connect it to the steel line coming up the frame (at the back of the cab), take the line off at the carb & try, if this doesn't get fuel to there, put on your rig can before the pump & try again. If this gets you fuel...drop the tank, there will be where your problem is. If it doesn't get you fuel, I would be suspect of a hose/line kinked/plugged. Once you have fuel to the carb, I would try installing the mechanical fuel pump...it will most likely work. ;) Lorne       

Offline Cowman85

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Re: Elec fuel pumps
« Reply #16 on: April 17, 2009, 07:51:11 pm »
lol flat cam lobe kid, got a nice ring to it.
I put the pump just under a foot away from the switching valve, as close to the tank as i can get with this pump.
When i got the precious pump put on i had installed a larger gas tank on the passenger side as well, so i know the tank is good.
The test i did with the jerry can tells me that there is just too much line for that little pump to pull, i tried both tanks as the passengers side is a few feet closer to the pump.
It is a small pump and thats what i was afraid of, the guy at napa just didnt fully understand my application i guess.

"put on your rig can before the pump & try again" what did you mean by rig can?
86 C20 350/TH400 LWB
80 C2500 350/Muncie SM465 *gone to heaven* LWB
98 Malibu 3.1 V6
86 S10 L99/4L60E

Offline choptop

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Re: Elec fuel pumps
« Reply #17 on: April 17, 2009, 08:56:17 pm »
I am beginning to wonder if you have a problem with your pickup tube. The pumps shouldnt run dry because the engine used to much fuel. It almost sounds like its sucking air either at or before the switching valve or the pickup tube.
76 C10 Choptop,76 C10 Swb
85 C10, 85 K10, 85 K20,86 C10,86 K10 (all extended cabs)
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Offline Cowman85

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Re: Elec fuel pumps
« Reply #18 on: April 17, 2009, 08:57:53 pm »
so you think that the pump is enough to run it no problem?
86 C20 350/TH400 LWB
80 C2500 350/Muncie SM465 *gone to heaven* LWB
98 Malibu 3.1 V6
86 S10 L99/4L60E

Offline HAULIN IT

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Re: Elec fuel pumps
« Reply #19 on: April 17, 2009, 11:19:07 pm »
"The rig can" was just another name for your "jerry can". It would seem unlikely that both sides would act the same if the problem is at the tanks, however one think to be aware of...It is easy to end up with a kinked shut supply hose coming right out of the sending unit. If the hose is not routed carefully or if the hose was made a little long to aid in hooking it up, this can happen...ask me how I know, on second thought, don't  ;) My plan would be the same as earlier. Get back near the tank & put in your pump (by-pass the switching valve) straight to the steel supply line going to the front & try it. If it doesn't run...Put the "in" side of the pump in your "jerry can" & repeat. Good Luck, you'll get it figured out, Lorne   

Offline Cowman85

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Re: Elec fuel pumps
« Reply #20 on: April 18, 2009, 02:03:25 pm »
go figure never heard them called a rig can before.
since the truck was running fine before when the previous electric fuel pump was on i am leaning toward this pump being to small. It is only the size of a computer mouse.
i could see it pulling off just the one tank like you suggest but i need the second tank for out of town trips so it wouldnt work out in the end for me, i think i will go guy the 97gph holley and hook that up, besides there is no way the new pump will make more noise than this little firecracker!
but when i'm down there i will check it all out anyways, thanks for the help  :)
86 C20 350/TH400 LWB
80 C2500 350/Muncie SM465 *gone to heaven* LWB
98 Malibu 3.1 V6
86 S10 L99/4L60E

Offline HAULIN IT

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Re: Elec fuel pumps
« Reply #21 on: April 18, 2009, 03:12:24 pm »
Ok, I went back & read your other post about the whole fuel pump, cam lobe, rip-off guy, ect. A few things of question. So you/he removed the fuel pump that he put on after the dispute over the cost, Is this correct? The truck ran correctly while this pump was in place, correct? Where was this pump mounted & what all has been changed, R&I'd, ect. since that time? Are you saying you are trying to suck from both fuel tanks at the same time? I would like to see you try the one tank/jerry can as a diagnoses to your problem, once that is figured out, you can hook up both tanks if you like, but it needs to be through a known good switching valve. You mentioned money is a little tight, testing to be sure your buying the part you need costs little/nothing...I suggest you do a little more figuring, even a little pump should have enough umpha to run the engine at idle sitting still unless your "lift" is too severe.

I put the pump just under a foot away from the switching valve, as close to the tank as i can get with this pump.

Was the pump before (on the tank side) the switching valve or after (between the valve & the carb)? Was the valve by-passed while you did this?

Offline Cowman85

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Re: Elec fuel pumps
« Reply #22 on: April 18, 2009, 09:03:44 pm »
the only things changed are the fuel pump and a new tank on the passengers side, the pump was removed. The switch valve has always worked fine.
The pump was in the same place as the new one, and everything was running fine before the pump was removed, thats why i think the pump is not strong enough for this place in the line. I will be testing to make sure though, i dont want to spend the money if i dont have to.
I just cant see that pump pulling all the way through the valve etc, thats why i was skkeptical of it to begin with, there is also a bit of a long loop of hose near the valve to make it easier to test for now.
86 C20 350/TH400 LWB
80 C2500 350/Muncie SM465 *gone to heaven* LWB
98 Malibu 3.1 V6
86 S10 L99/4L60E

Offline Cowman85

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Re: Elec fuel pumps
« Reply #23 on: April 21, 2009, 07:19:35 pm »
alright, the new holley pump (97pgh 7psi) has done the job, bolted in and hooked up the truck started no problem and runs great.
86 C20 350/TH400 LWB
80 C2500 350/Muncie SM465 *gone to heaven* LWB
98 Malibu 3.1 V6
86 S10 L99/4L60E

Offline choptop

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Re: Elec fuel pumps
« Reply #24 on: April 21, 2009, 09:04:44 pm »
Great, glad you got it. ;D
76 C10 Choptop,76 C10 Swb
85 C10, 85 K10, 85 K20,86 C10,86 K10 (all extended cabs)
86 C30 extended crewcab

Offline TexasRed

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Re: Elec fuel pumps
« Reply #25 on: April 21, 2009, 09:09:15 pm »
I woulda thought the other pump woulda worked ok, that's a little weird. But yeah, glad you got it worked out.

Offline Cowman85

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Re: Elec fuel pumps
« Reply #26 on: April 22, 2009, 10:18:53 am »
thanks for the help guys its appreciated  :)
86 C20 350/TH400 LWB
80 C2500 350/Muncie SM465 *gone to heaven* LWB
98 Malibu 3.1 V6
86 S10 L99/4L60E

Offline HAULIN IT

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Re: Elec fuel pumps
« Reply #27 on: April 22, 2009, 10:23:19 pm »
Good Deal! Glad to see you beat it.