I believe that this truck has a automatic fuel tank switch. There is a fuel return line that runs to only to 1 tank and this tank is the 1 that has to be used first. For some reason the wrong tank is being uses after fill-up. The hard cranking is the fuel pressure is bleeding down when the engine is off. Maybe a bad fuel pump.
A friend of mine has a 90` F150 Lariat 5L v8 2wd. Truck starts only after
> the 3rd crank and he has problems with the dual tanks...fuel migrates from
> one tank to the other and at times after fill up gas will splash out of the
> filler cap while driving. Any ideas?
> Thank you
> Boris
>
>
On Wed, 31 Mar 2004 20:04:45 -0600, Doc rearranged some electrons to form:
The fuel flow is controlled by a mechanical shuttle valve that switches depending on which tank is pumping fuel (there is a low-pressure pump in each tank).
Replace the pump in the tank that is running over. There is no shuttle valve, there is no mechanical valve. The lines are simply "t'd" together and the system depends on check valves in the pumps to prevent what is happening to yours.
There is an electric tank switching valve on your truck. The '90 model was recalled because of exactly the problem you have. I would imagine the recall has expired on your vehicle although, some safety recalls never expire which may be the case with this recall. I would contact the dealer if you have a reliable dealer. You may also want to contact Ford if the dealer declines the recall service because of mileage or age. They may be right. Ask to see the recall notification at the dealer for conditions. If that fails, you will have to replace the valve anyway to correct the problem.
Well my '59 F150 certainly has a mechanical shuttle valve - called the 'dual function resevoir'. It is a simple system which must have survived for a few years.
On Fri, 02 Apr 2004 04:17:32 +0000, David M rearranged some electrons to form:
How about that, they changed it in 1990 on F150s. Here's the recall notices:
NHTSA ID No.: 91V-146 Date of Company Notification: 9-4-91 Make: Ford Model: Econoline Model Year: 1989-91
---> Model: F-150, F-250, F-350
---> Model Year: 1989 Number of Vehicles: 350,000 Mfg. Campaign No. 91S39. Fuel tank, auxiliary. DOM: 2/89-2/91.
--- >Dual function fuel reservoir [aka shuttle valve] may malfunction and cause an overfill condition in one of the fuel tanks, resulting in an overflow of fuel past filler cap. Overflow of fuel past filler cap causes a fuel leakage, which can result in fire when exposed to a source of ignition. Correct by replacing dual function fuel reservoirs with new reservoirs containing o-rings of a revised material.
NHTSA ID No.: 93V-125 Date of Company Notification: 08-02-93 Make: Ford Truck Model: F Super Duty Model Year: 1991-93
---> Model: F-150
---> Model Year: 1990-93 Model: F-250 Model Year: 1990-93 Model: F-350 Model Year: 1990-93 Number of Vehicles: 1,131,000 Fuel tank assembly. DOM: 7/89-12/92. Light trucks and chassis cabs with gasoline engines and dual fuel tanks.
---> A malfunctioning check valve within the fuel pump assembly causes a portion of the unused fuel from one tank to be returned to the second tank. When this occurs, the capacity of the second tank can be exceeded, causing fuel spillage which can result in a fire. Correct by replacing the fuel pressure regulator and installing redundant check valves.
'When something ain't broke then fix it'. They replaced a simple system with a complicated one. Previously switching tanks meant directing power to the low-pressure pump in that tank. The dual function resevoir did the rest. No problems, no recalls (as far as I know).
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