87 no fuel issue. Trouble shooting data gathered (prior data false)

[weider1717]

Started a new thread due to false data on the other thread.

87 with dual tanks since the 90's the right tank has not worked.

truck was parked running with switch set to left tank 1 year later will not start due to not getting fuel. Can pour fuel into the TB bowls and it will start.

broke loose the fuel filter (initially appeared to put some fuel out after priming and turning over while fuel line broke loose at front towards the engine) however now with the fuel filter completely removed turning the switch on AND turning it over trying to start is not pumping any fuel from the line where the filter is missing. Assume that fuel I thought was coming out must have been some left in the line and ran out while I was trying to start it (making me have false data)

When you turn the switch on you can hear the fuel pump prime for about 2 secs then shut off when set to the LEFT tank as it always has been since the 90's. **The question here is with the fuel filter removed shouldn't I be seeing fuel pumping out where the fuel filter is removed if I can hear the pump prime? and shouldn't it continue to pump since it's not dead heading and the filter is gone?

FUEL VALVE: the valve DOES work however seems like the right tank pump has been bad for years since the 90's. It does NOT swap EVERY TIME I flip the switch but about 25% percent of the time it WILL swap and also noted the fuel gauge goes high way more than full whenever it does finally swap to the right tank. I took my air compressor and shot air back towards the tanks with the switch in either position both yielded air being felt at the left tank with it in the left position and right tank when in the right position so there are no clogged lines.

I am starting to think both pumps are bad and the left one went bad while setting this year but again I can hear it prime up for a couple seconds when the switch is turned on but I would have assumed i should be seeing gas come out at the line where the fuel filter is removed and to keep pumping but that is not the case.

so can i hear it pick up and prime yet get no gas to come out of the line?

The above proves its the filter back not anything with the injectors like I first thought…

this is not a swapping from tank to tank issue so don't misread it the issue is no fuel when swapped to either tank and the left one has always worked and still primes up but not showing fuel where I took the filter off at.

hopefully I have provided more clear data and maybe someone could help me better.

[f.monroe]

I would maybe put 5 gallons of fresh gas in the tank with the running pump and try again.
Frank

[weider1717]

anyone now how it should be reacting with the filter out?

[hatzie]

The LH pump makes noise like it's running but not the RH?

With the LH tank selected on the dash... If you remove the inlet hose from the LH tank to the inlet side of the valve do you get fuel in a catch can when you switch the ignition on?

[chebyshortbox65]

Same problem on a 90 TBI square body dually pulled sender unit and found rubber line in tank was bad pump came on to prime with key on replaced pump and hose good as new

[weider1717]

Originally Posted by hatzie

The LH pump makes noise like it's running but not the RH?

With the LH tank selected on the dash... If you remove the inlet hose from the LH tank to the inlet side of the valve do you get fuel in a catch can when you switch the ignition on?

left tank selected fuel filter removed switch on no gas comes out, try starting it still no gas comes out where fuel filter is removed.

[f.monroe]

I think what he is saying is to remove the line from the inlet side of the switching valve so it's just a discharge line coming from the tank with nothing else to restrict the flow. If it flows at that point you know the switching valve is blocking the flow. If there is still no flow then it's time to drop the tank and look inside.
Frank

[weider1717]

Originally Posted by f.monroe

I think what he is saying is to remove the line from the inlet side of the switching valve so it's just a discharge line coming from the tank with nothing else to restrict the flow. If it flows at that point you know the switching valve is blocking the flow. If there is still no flow then it's time to drop the tank and look inside.
Frank

gotcha, read too fast I guess. thanks, will try tomorrow before removing the bed.