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Hey guys i need some help me and my friend are helping a guy by fixing his old 1983 Ford Ecoline 350 Citation motorhome..it has a 460 4 bbl carb motor. Well from what we were able to do today is followed the gas lines from the carb down to the frame rail where they went into these black boxes..which we are assuming are filters then they go to the tanks(dual tank) We took one of the lines off and turned it over no fuel was getting through. Also we couldnt hear the pumps prime..but they worked fine when he parked it so we want to start with sensors or anything like that. So if anyone has a wiring diagram for one of these of any information that could help us out, it would be great thanks
Ps. we checked the fuses we could find and they all looked good.
Sounds like you are working on the wrong system.
The black boxes a lines are the fuel vapor system and not the fuel supply system.
Does the engine have a fuel pump on the side of the block or does it have electric fuel pumps in each tank?
If it has electric pumps it will also have a motor drive fuel selector valve on the frame.
Does it have a "T" on the fuel line just in front of the carb with both lines going back to the fuel selector valve?
Let me know what you find and then I will post the right diagrams.
Ill go take another look at it today to find out...but where is the fuel selector valve? from what i remember there was no t.but it was hard to tell as theres very little room around to see. i do believe its in take fuel pumps for the front tank we see some wires going up above the tank and then going down the frame rail....now just a question of curiosity what is a fuel vapor system? im assuming we will need to re-hook up that hose to get it to start? thanks for the help
I used fuel vapor system as I thought maybe that would be easer to understand.
It is called the Evaporative Emission System.
Fuel Tank Venting
Fuel vapors trapped in the sealed fuel tank are vented through the orificed vapor valve assembly in the top of the tank. The vapors leave the valve assembly through a single vapor line and continue to the carbon canister (located in the engine compartment or along the frame rail) for storage until they are purged to the engine for burning. The carbon canisters is what you see as black boxes.
Canister Purging
Purging the carbon canister removes the fuel vapor stored in the carbon canister. Purging occurs when the engine is started.
Maybe the photos below will help you answer the above post questions.
The fuel selector valve if it has fuel pumps in the tanks would be bolted on the frame near the tanks: