I was told there are 2 gas pumps,replaced 1 and cant find other. problem is that the gas flow seems to be not working correctly..it is a dump truck.what is problem and where is other pump?

This vehicle has no mass air flow sensor , it uses a MAP sensor for speed density fuel control , My self I would hook up a scan tool an see what the block learn an integrator or showing , this is same as fuel trims on OBD2 vehicles I would also look at the map sensor voltage parameter ! A bad map sensor can cause a lot of fuel to dump into the engine ! Manifold Absolute Pressure MAP Sensors

you have 2 options
1--- put the fuel return line into the tank you are using
2--- install a balance line between tank 1 and tank 2 so that the fuel back to tank1 is allowed to balance back into tank 2

properly set up the tanks should be connected so that the fuel gauge reads the total fuel in the tanks and there is a need for only one fuel pump

It is not necessarily the flow of gas that is important. You need at least 40 pounds of pressure for the injectors to operate correctly.

i'm assuming you disconnected the fuel line and placed the line in a container to catch the fuel when observing the flow.

it might sound strange but i think there might be a leak in the tank coming from the fuel pump assembly. it's possible a tube or hose is broken on the assembly and the pump is just pumping the gas back into the tank.

there's flow because there is no pressure building up with the line disconnectedand the gas flows. when connected, pressure builds and blows out the break in the tube or hose.

No second fuel pump, note that it's common for the wire harness from the gas tank to the frame to go bad when manipulated to replace the fuel pump from the gas tank which is only a $15.00 replacement part. The fuel filter should also be replaced shortly after to ensure any dirt that got in the gas tank that the filter will collect will not restrict the flow of fuel to the engine. Good luck and keep me posted, be glad to answer any questions you may have.

1-The Gauge reading is not correct, Maybe the fuel level is too low to run but it didn't not report empty.
2- The fuel filter has not been changed causing the pump working harder when low fuel volume flowing in the line.
To be safe, replace the Fuel filter to have a piece of mind. After that if it still happen then I would not worry about as long as I fill up at 1/4 level. The filter is mounted on the chasis the driver side.

Check the fuel filter and fuel pump. If the fuel filter is dirty it will restrict the flow of gas to the injection. Also check the fuel pump pressure to make sure it is still working correctly.

After you dump the fuel in the throttle body it will continue to run on its own or die as soon as it burns up all the fuel you dump in? Do you have access to (Noid lights)? Are both plugs attached to the distributor?

First, never use starting fluid on a gasoline engine. Check for dirty air filter, then check for Mass air flow sensor (Fault code) . This sensor controls fuel mapping, bad signal here will cause over fueling (black smoke) also called loading up (rich). Stopped up Air filter will affect Mass air flow. Perform OBD II test to prevent buying unneeded parts. Also delete stored codes.

if u replace all plug wires witch should be done not just 1, then if you are having the same problem your fuel pump maybe to weak to push the fuel to the engine