Jeff Stich
True Classic
As part of the ever-ongoing rebuild of my 850 Sport Coupe, I'm converting the fuel delivery system from a mechanical pump to an electric pump. When I've done this on my 850's in the past, I simply ran a wire from the "+" terminal on the ignition coil to the electric pump in order to power the pump. Works great, but not so safe in an accident.
For this install, I figured I'd do a safer conversion by adding an emergency cut-off switch to automatically kill the power feed to the pump in case of an accident. Some folks use an engine oil pressure-activated switch to do this, which cuts power to the pump if the oil pressure dies (due to engine shut-off). Nice to have, but what if the engine doesn't just die?
Instead, I'll be using a "modern" roll-over safety valve (aka: fuel pump inertial switch) to cut power to the electric pump. This way, pump power will be cut upon impact should the car be involved in an accident, so the pump won't be dumping fuel (causing a fire) & the engine will (eventually) turn off (die) from fuel starvation. These switches come in various shapes & sizes, some inexpensive & some not. I'm using the factory switch found in various 2000-on Ford vans/suv's/cars (E-350, E-250, Expedition, Excursion, Mustang, etc.), mainly because they're cheap & widely available in my local junkyards, & simple to install. The one I'm using looks like this:
I've mounted the electric pump on the left engine bay wall, where the VIN tag is normally located on early 850's. For easy access & testing (if ever necessary), I want to mount this switch in the engine bay, preferably near the fuel pump. Problem is, this switch is too "modern" looking & just plain fugly to put in my 850 engine bay as-is, so I decided to disguise it by making a metal cover to fit over it. After a few failed attempts at making anything halfway decent-looking, an idea came to mind! I scavenged an old 903 (alternator) voltage regulator cover like this one from my parts stash:
I then cut a 3/4" hole in the center of each small end of the cover. After trimming off the 2 upper screw mounting tubes from the roll-over valve, it fits inside the voltage regulator cover, with the round red button sticking out of one of the holes I just cut, & the wiring sticking out of the other hole. The button is exactly 3/4" diameter, & the wiring plug is slightly smaller in width, so the holes are a perfect fit. I sandblasted the cover, filled-in the stamped wiring numbers with Bondo, then sanded it smooth & repainted it (black). One of the covers' original base mounting screws was moved up to the right side in order to fasten the internal (fabricated) bracket in place, & a regular 850 rubber wiring grommet was used where the wires exit the cover.
When mounted in the car, the cover sits sideways (vertically) just like normal for a 903 voltage regulator. The red reset button is now on "top", with the wiring exiting the bottom, & the FIAT script reading sideways (some say "Magneti Marelli", some say "FIAT" like the one shown - I chose a "FIAT" one). I'm thinking of using a paint pen to highlight the "FIAT" script on the cover, so it'll look like the whole thing is something that's supposed to be there (ie: factory). Can't decide what color to use for the script - Silver? White? Yellow? Red?
I plan on mounting the assembly on the left inner fender wall of the engine bay, a few inches above the side frame rail & 1"-2" forward of the yellow Cavis fuel filler tray drain hose. This will put it in an easy-to-reach location, yet make it inconspicuous enough to look like it "belongs" there. I'll also need to add a fuse, a relay & some additional wiring, which I'll try to post an update of later.
For this install, I figured I'd do a safer conversion by adding an emergency cut-off switch to automatically kill the power feed to the pump in case of an accident. Some folks use an engine oil pressure-activated switch to do this, which cuts power to the pump if the oil pressure dies (due to engine shut-off). Nice to have, but what if the engine doesn't just die?
Instead, I'll be using a "modern" roll-over safety valve (aka: fuel pump inertial switch) to cut power to the electric pump. This way, pump power will be cut upon impact should the car be involved in an accident, so the pump won't be dumping fuel (causing a fire) & the engine will (eventually) turn off (die) from fuel starvation. These switches come in various shapes & sizes, some inexpensive & some not. I'm using the factory switch found in various 2000-on Ford vans/suv's/cars (E-350, E-250, Expedition, Excursion, Mustang, etc.), mainly because they're cheap & widely available in my local junkyards, & simple to install. The one I'm using looks like this:
I've mounted the electric pump on the left engine bay wall, where the VIN tag is normally located on early 850's. For easy access & testing (if ever necessary), I want to mount this switch in the engine bay, preferably near the fuel pump. Problem is, this switch is too "modern" looking & just plain fugly to put in my 850 engine bay as-is, so I decided to disguise it by making a metal cover to fit over it. After a few failed attempts at making anything halfway decent-looking, an idea came to mind! I scavenged an old 903 (alternator) voltage regulator cover like this one from my parts stash:
I then cut a 3/4" hole in the center of each small end of the cover. After trimming off the 2 upper screw mounting tubes from the roll-over valve, it fits inside the voltage regulator cover, with the round red button sticking out of one of the holes I just cut, & the wiring sticking out of the other hole. The button is exactly 3/4" diameter, & the wiring plug is slightly smaller in width, so the holes are a perfect fit. I sandblasted the cover, filled-in the stamped wiring numbers with Bondo, then sanded it smooth & repainted it (black). One of the covers' original base mounting screws was moved up to the right side in order to fasten the internal (fabricated) bracket in place, & a regular 850 rubber wiring grommet was used where the wires exit the cover.
When mounted in the car, the cover sits sideways (vertically) just like normal for a 903 voltage regulator. The red reset button is now on "top", with the wiring exiting the bottom, & the FIAT script reading sideways (some say "Magneti Marelli", some say "FIAT" like the one shown - I chose a "FIAT" one). I'm thinking of using a paint pen to highlight the "FIAT" script on the cover, so it'll look like the whole thing is something that's supposed to be there (ie: factory). Can't decide what color to use for the script - Silver? White? Yellow? Red?
I plan on mounting the assembly on the left inner fender wall of the engine bay, a few inches above the side frame rail & 1"-2" forward of the yellow Cavis fuel filler tray drain hose. This will put it in an easy-to-reach location, yet make it inconspicuous enough to look like it "belongs" there. I'll also need to add a fuse, a relay & some additional wiring, which I'll try to post an update of later.
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