fuel problems

[RicoTizzio]

I'm new to the group,glad to be a part. I have a 84 Chevy swb 5.7 eng. I installed an electric fp,my pump is coming on but no fuel to the carb. I have two tanks the pump is right before the tank switching device. Any help is greatly appreciated

[markus]

i'd check for the flow direction, maybe it's put in the wrong way (soaking air into the tank). if everything is ok with installation then check the tank selector valve and make sure it is open to the tank you have gas in. if this doesn't get you to the solution then fill the pump with gas, it might have trouble soaking air first.

btw, why before the selector valve? doesn't that mean you only pump out of one tank?

[codyC10kid]

If it is a gravity feed pump the pump should be located below the tank...I just put my gravity pump in yesterday but i also have a 20 gal. square tank in the box and the pump is on the frame

[RicoTizzio]

I have the 50 dollar pump by Mr gasket. I put the pump on the frame right by the tank selector so that what ever tank is open would pump. Did i put in the wrong place. I've hooked up one before but never on a dual tank

[RicoTizzio]

And when i cut the metal gas line it was wet. Mind you this truck has set for 8 plus years

[markus]

as far as i can see the fuel pump you bought ($44, #12s or 42s) is a self priming pump, should work then. if the truck has been sitting for 8 years, have you checked that there's any gas? try to rule out the valve by connecting the pump directly to either of the tanks (means to one of the hoses connecting to the valve's intake) to see if the line between the tank and the valve works. if it does probably your valve is stuck or blocked or whatever and you change it and be done.

btw, gas tank cleaning and gas changing is a good idea after all these years...

[RicoTizzio]

Well i bought some b-12 to pour in the tank i put octane booster n some fresh gas n let it sit for a day. I will put more gas n try to by pass the selector. The pump is a 12s

[jaredts]

I am still curious about Markus's remark:  how could you hook up the pump before the selector valve?  Fuel gravity feeds to the selector valve from two feed lines--one from each tank.  I would expect you to put your pump in just after the valve to pump from the single feed line to your carburetor.  Did you try unhooking the output from the pump and see how it pumps into a bucket?

[HAULIN IT]

I have two tanks the pump is right before the tank switching device.

I am still curious about Markus's remark:  how could you hook up the pump before the selector valve?  Fuel gravity feeds to the selector valve from two feed lines--one from each tank.  I would expect you to put your pump in just after the valve to pump from the single feed line to your carburetor.

I think jared is on the right track. The original pump is ahead of the selector valve. If you put it before the valve, if you have the switch on "the other" tank...the pump would deadhead into the selector valve & give you no fuel to the carb. The pump should be after the selector valve. Lorne

[RicoTizzio]

Don't mean to sound like an air head. But are you guys saying that putting the fuel pump right on the frame next to the selector is a bad idea? I think i may have found the problem. I unhooked the lines to the fp put one end in a gas can n it pumped gas. I tried to blow thru the metal line via mouth guess not enuff psi lol. My helper couldn't feel no air coming from the line,im thinking the line is clogged. Could i use fuel hose at a local parts store just to try to get it running?

[RicoTizzio]

When i said i put the pump right in front of the selector,im talking about between the metal line coming from the carb n the switch

[markus]

I am still curious about Markus's remark:  how could you hook up the pump before the selector valve?  Fuel gravity feeds to the selector valve from two feed lines--one from each tank.

In my case the selector valve is above the tanks, levelwise spoken. Still though, case it is below, the outlet of the tank is on top, so you wouldn't expect the gas to just spill out till the tank is empty, you'd have to soak first. anyhow, caution is a good advise here  what i meant to try is figuring out if the gas can make its way through hoses and lines to the valve, from each tank.

Could i use fuel hose at a local parts store just to try to get it running?

that's next, if you rule out problems from tank to valve and the valve itself, bypass the line that's probably clogged and try feeding the carb with a hose. wouldn't do it permanently, since the metal lines are more rigid and less heat sensitive. try to get out of the line whatever is in there, compressed air may be a good thing to start with.
if you bypass with a hose don't forget to put a fuel filter in the line, you don't want to pass the dirt directly to the carb (which you probably have to clean out anyways, after 8 years of sitting).

But are you guys saying that putting the fuel pump right on the frame next to the selector is a bad idea?

not in my opinion, i first thought you had put it in line before the selector valve (means between tank and valve), but i now understand that it is in line after the valve. for diagnostic reasons it might be better to have the pump in the engine compartment, but should be ok where it is now. again: don't forget the fuel filter, and change it once you got everything up and running, don't save that buck 

another remark: don't know if your system originally was equipped with a pressure regulator and a line back to the tank(s), if so it's not a bad idea at all to build it up again that way, so you always get fresh and cool gas to your carb, helps a lot in ugly driving conditions (high temperatures, low speed).

[RicoTizzio]

Ok so i temporarily bypassed the metal line and the selector,no fuel. But i connected a hose from a gas can to the feed on the pump i got fuel but it didn't fill up the inline filter just went half full. Could the pump be bad or weak,the battery has 12.88 volts?

[markus]

sounds as if the fuel doesn't want to get out of the tank. you may connect a hose to the line coming from the tank, before the valve and try to soak or pump, to see if there is a blockage. maybe your valve is blocked, that'd be another possibility. no problem with the half full filter, that's normal.