Observations of '03 fuel pump

Discussion in 'SN95 V6 Mustang Tech' started by 91ranchcoug, Apr 2, 2013.

  1. I have installed an '03 3.8 in a Model A and originally modified a TANKS '32 style gas tank to use the factory style '03 fuel pump. This was originally done in '04 and this spring the tank developed a leak. TANKS has since developed a in-tank pump module for the '32 style tank which I wound up using by installing a slightly modified pump from the '03 factory unit along with some fancy metal tubing.

    The '03 factory pump unit consists of a pint sized container with the actual pump inside. It took me a while to figure out what all of the plumbing was for but this is what I have come up with. At the top of the conatiner holding the pump there is a "T" in the output line which connects to a tube that goes back down to the bottom of the container with the bottom end being on the outside. It then connects to an elbow and "T" that has a .020 (drill size #76) bleed hole which is not visible unless you cut the "T" apart. The bottom of the "T" connects to a filter and the other end has another elbow that connects to another tube that goes back into the pint sized container. The second elbow has an odd shape on the inside and I believe that it acts like a venturi when at operating pressure of 39 psi which is maintained by a small inline regulator located between the pump and the outlet tube. This means that the pump is always running when the key is on and filling or over-filling the pint sized container. The container has holes in the top so that pressure cannot build up inside. There is also a valve in the bottom of the container that allows fuel to enter the container if the exterior filter becomes plugged preventing the venturi system from filling the container. There is also a filter attached to the bottom of the pump inside the container which would catch contaminats if the exterior one becomes plugged.

    Remember that is a single fuel line voltage modulated pump. Originally I considered simply connecting the pump to the outlet line but then wondered how that situation would be seen by the CCR module since factory specs call for the pump to run continuously because of the bleed port when the key is on without the engine running. Since no fuel is being moved through the pump would the CCR shut the pump off, burn it up, cause a short???? Being a better plumber than computer geek I decided to plumb the new install with the factory regulator and .020 bleed. The regulator can readily be inserted on the output line and by carefully cutting apart the bottom elbows and "T" I was able to machine a small plug from the piece containing the .020 bleed which is held in place by the end of a short piece of 1/4 inch copper tubing and ferrel attached to a 1/4 inch brass compression fitting soldered to the steel tubing between the pump and the regulator. The bleed simply returns fuel to the tank and everything works fine. Sorry I did not take a picture.