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5th Wheeling
Joined: Jul 2017
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1986 F250 7.5l. Cranks no fire. New carb, new fuel filter, new fuel pump. Put gas in carb....fires right up. Fuel isnt getting to the carb and yes....theres fuel in the tank.Anyone experience this?
Lead Driver
Joined: Apr 2002
Posts: 5,240
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Which fuel pump do you have? In tank or mechanical engine mounted? Have you tested the fuel flow and pressure? Many reports of bad out of the box. Could be a stuck float valve in the carburetor. Plugged fuel filters.
Tuned
Joined: Dec 2023
Posts: 330
Likes: 185
I don't have an '86 to look at but if it has a fuel pump relay (I think '86 was the first year for F.I.) swap the relay with a known good one. I had a later model Dodge Ram 2500 I got cheap because of it dying. I was sitting filling some paperwork out and noticed some odd noises coming from the rear of the truck. A vibrating like an itty bitty jack hammer. On Dodge, and Fords and even Chebbies, there are few mechanical parts moving in the rear. The relays are the same for several systems. The fuel pump was next to the a/c relay. The noise went away. I got a new relay and swapped the a/c back where it was originally and put the new one in for the pump. No more noises and it never died again as long as I owned the truck.
Tuned
Joined: Dec 2023
Posts: 330
Likes: 185
My '85 is carbureted but it has an electric fuel pump. It has what looks like a factory block off plate on the engine so I'm assuming the '86 is the same way. I would still double check the fuel pump relay if for no other reason than to eliminate it as a problem.
Moderator
Joined: Jan 2001
Posts: 56,949
Likes: 2,718
From: Virginia
The 460 fuel system can be very trouble prone depending on which fuel system you have. They had dual tank with mechanical pump as well as single tank, and dual tank with electric fuel pumps as well as single tank with one electric pump. The electric pump versions have the pump in the tank. Which do you have? The electric pump systems are complex with many failure points.
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