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1984 250 460 dual tank- trouble priming fuel lines
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1984 250 460 dual tank- trouble priming fuel lines
 
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Re: 1984 250 460 dual tank- trouble priming fuel lines
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I'll bet you are frustrated.
 First, before going any further and before I forget, when you get this sorted out you may need to put a fuel pressure regulator on. Edelbrock's don't like more then 6 psi and the electric pumps can give too much pressure and overpower the floats, especially at idle. But, that can wait as you need fuel first. Anyway, to troubleshoot I would break the system down and test it section by section. Pull the line from either the front or back tank off the selector valve and see if you get fuel there. If so, but it back on and pull the line leaving the selector valve - do you get fuel there? If so, keep going. But I doubt you'll get that far before finding the problem. And, I'm suspecting the selector valve is the problem since it is a common thing in the issue. Maybe it is bad? Maybe there's a wiring problem? By the way, those pumps aren't supposed to have full voltage other than when starting. There is a resistor in the line when in Run. I don't think you hurt them as the engine wasn't running and the voltage would have been something like 12 volts instead of the 14 volts with the engine running and the fuse link straight to the battery. But, I wouldn't want to run them a long time with full voltage.
Gary, AKA "Gary fellow": Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
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Re: 1984 250 460 dual tank- trouble priming fuel lines
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In reply to this post by '84-460-Project
 I had an intermittent problem getting fuel on my truck. The connector for the oil pressure switch is bad. It's on the back of the engine. IIRC the sender for the gauge is there also. I don't know if the wire color is the same on a 1984 as my manual is for my 1986. After the engine starts this keeps the Fuel Pump relay on. You could try jumpering the connector.
Dane
1986 F250HD SC XLT Lariat 4x4 460 C6-Sold 1992 Bronco XLT 4x4 351W E4OD 1998 GMC Sierra SLE K1500 350 4L60E Arizona |
Re: 1984 250 460 dual tank- trouble priming fuel lines
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In reply to this post by '84-460-Project
Having lived with one of these for quite a while (1986 F350) I am pretty conversant with the system. The Hot Fuel Option Package T valve with blue dot. Mine had a 6 port motor operated valve that controlled both the supply and return lines, the pumps in these are extremely low pressure, spec calls for 5-7 psi so the two filters may be too much restriction. Can you hear or feel the selector valve switching? I just figured out what you are calling the T valve, it is the vapor separator and has an orifice where the 1/4" line attaches.
Other question, can you hear the pumps run? they make a not super loud whine, like a fan motor only muffled because they are submerged in the tanks. Fuse #18 is the pumps through the tank selector relay, fuse #15 is the tank selector valve control. Here are the diagrams, if they aren't easy enough to read I can email them to you.  
Bill AKA "LOBO" Profile
"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413 |
Re: 1984 250 460 dual tank- trouble priming fuel lines
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Re: 1984 250 460 dual tank- trouble priming fuel lines
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Re: 1984 250 460 dual tank- trouble priming fuel lines
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Re: 1984 250 460 dual tank- trouble priming fuel lines
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Re: 1984 250 460 dual tank- trouble priming fuel lines
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Re: 1984 250 460 dual tank- trouble priming fuel lines
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This post was updated on .
In reply to this post by '84-460-Project
First question, do you know how to read a wiring diagram? Not trying to be nasty, some people do not know how to read them. On the pressure regulator, Gary put his just before the carburetor.
Now to the other question, you said the new pump is a lot louder than the old one, are you sure it is the correct pump? A lot of places will try to sell you the mid 1985 through 1989 low pressure EFI pump which is way too high for a carbureted engine (ask Gary Lewis and I how we know). They are much noisier as they are gearotor pumps and the originals are centrifugal pumps. The fact that you had fuel from the front tank, switched and nothing from the rear, then when you went back to the front, still nothing makes me suspect the selector valve isn't moving, it doesn't release the fuel, just connects the desired tank to the engine fuel lines. When you rerouted them, you didn't get them crossed did you? The larger line is supply, smaller is return, the valve has 6 ports two for each set of lines. The selector valve on yours should be like mine was and have 5 wires going to it. On front tank the brown with white wire should have power in run, in rear tank the orange wire should have power in run. The remaining 3 wires are the fuel gauge wires, yellow with white to the gauge, yellow with light blue hash, rear tank sender, dark blue with yellow, front tank sender. On the switch mentioned, it is on the back of the engine, on a hex shaped fitting with the oil gauge sender (large dome with a single stud). It is a smaller switch with a molded shell that a two lead wire goes into. Here is a picture showing where the wiring runs, switch is visible as the black item where the red line goes on the back of the engine.  Inertia switch is just to the passenger side of the floor hump on the heater duct, it has two yellow wires, but if either pump is running it is closed. With the key on, and nothing running (including the pumps, they should not run until the engine is cranked) you should be able to hear a pretty solid thump from the selector valve when you change tanks with the switch, when the switch is moved to the front tank position, you should also be able to hear the tank selector relay (on the firewall, underhood) click closed. The fuel pump relay will only close with oil pressure operating the switch.
Bill AKA "LOBO" Profile
"Getting old is inevitable, growing up is optional" Darth Vader 1986 F350 460 converted to MAF/SEFI, E4OD 12X3 1/2 rear brakes, traction loc 3:55 gear, 160 amp 3G alternator Wife's 2011 Flex Limited Daily Driver 2009 Flex Limited with factory tow package Project car 1986 Chrysler LeBaron convertible 2.2L Turbo II, modified A413 |
Re: 1984 250 460 dual tank- trouble priming fuel lines
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Re: 1984 250 460 dual tank- trouble priming fuel lines
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Re: 1984 250 460 dual tank- trouble priming fuel lines
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Re: 1984 250 460 dual tank- trouble priming fuel lines
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Re: 1984 250 460 dual tank- trouble priming fuel lines
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Re: 1984 250 460 dual tank- trouble priming fuel lines
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Yippee!!!
 Glad you got it going. One layer of the onion peeled, more to go. 
Gary, AKA "Gary fellow": Profile
Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
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Re: 1984 250 460 dual tank- trouble priming fuel lines
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Re: 1984 250 460 dual tank- trouble priming fuel lines
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