Hello I am Trying to diagnose a fuel issue and I am a bit confused. I have looked and many diagrams and information on here and its is great info. But here is my question since I cant seem to find the right diagram.

I have a 1987 Econoline E350 Cutaway RV, It has dual tanks
1. switch selector is on the dash with the ac controls.
2. it has a carbureted, 351W. it. with a mechanical fuel pump.
3. It does not seem to be pulling fuel. But rubs when fuel sprayed into the carb.

Yes good fuel in both tanks.

Here is my confusion. all the diagrams I have been able to find only reference electric fuel pumps in both tanks. with a switch over valve inside the frame. but none that i can find show the mechanical fuel pump in line with this. Its just confusing is the system electromechanical or just straight mechanical. or is the switch over also a pump and a valve switch are there really pumps in the tanks??

Thanks in advance
Mike.

 

My 89' has in tank electric fuel pumps and a fuel tank selector valve on the frame rails. The valve has 5 ports. No additional fuel pumps of any kind are present. Trying to find a replacement valve for the original part. I broke off a port nipple by accident with floorjack.

 

I have no idea of multiple pumps, low pressure vs the high pressure. The resivoir thing is also a mystery. Not sure what's what, and how do I figure this out...