U/SA 302 ffffford build

[Cglrcng]

Hey Jim,

I will attempt to not write a whole book here, but will attempt to add a few suggestions since you have made the decision to make the tank to cell switch. Here is what I did.
Note: Our combos are very different (as mine is a 1980's pretty rudimentary EFI single point throttle body fuel injection system. Yours is not (but both our vehicle manufacturers have provided or not provided (depending on year produced), certain fuel system safety features that we may or may not be aware of when we start the process to delete and add to the "fuel system" we are allowed to convert/modify to achieve the switch to a cell.

I removed the tank and straps, fuel filler neck, and the associated in tank pump/ filter sock and upper tank vent and return line attachment and fuel filler neck and Grommet. I left the stock steel fuel lines and associated wiring alone at that point.

Then I stopped. I located (on ebay as dealers have pretty much sold off their old 1980's vehicle specific repair manual sets and they are plentiful and fairly cheap these days), a full set of vehicle specific repair manuals for my year, make, and model (including the complete chassis, trim, and wiring diagrams in a 3 book set for like $36.00 shipped). There were some surprises located in those books once I did a deep dive in that helped me make critical (as built safety items built into the existing fuel system I was not aware of prior to that date), decisions were soon made not to remove certain items or defeat their purpose in the name of safety.

I looked at the fuel system as a whole using the books as a reference and took pencil to paper then to diagram out both the as built system, and included a wiring diagram concerning the specific under dash to tank wiring and discovered a really important safety switch (a mercury activated rollover safety switch/relay), located under dash on passenger side. I then researched that particular safety feature and what it does and why (simply put key on the system pump is activated for the 3 second EFI pump prime, then turns over control to the ECM and PM.

But should the car be upended as in a rollover type accident and the key is on, and a tilt of the auto get to approx. 40 degrees of tilt or greater, the mercury rollover switch auto cuts off all power it the electric fuel pump.

At that point (I delved deep into the dash), not only located the switch, but took the time to test it to see if it still worked as designed by unbolting it from its position (hooking up a test light rig on the switch wiring output, went key on and then slowly rotated the switch to simulate an actual rollover...it worked flawlessly as built, and at about 38 degrees of tilt using a simple angle finder, key still on the mercury in the small glass bulb cutoff all power to the pump. I instantly made the decision to utilize in my second as intended design change diagram on paper the existing wiring system from battery all the way back to the removed tank location (to power my new Jegs pump and filter system), so as to not defeat that real world very important safety feature.

I looked at the real world as built system, the required NHRA minimum requirements and then on paper first re-engineered the final setup.

The new fuel cell was going into a hatchback car and required a bulkhead both top and bottom to isolate it from drivers compartment and from track/car debris, and even though the fuel cell came with an internal rollover valve on the vent line (that satisfied the NHRA rule), I went one step further and added another external rollover after the vent line exited the spare tire well.

Also pay attention to the NHRA required grounding between fuel cell and frame. In my case that it is a poly fuel cell and powder coated cell straps. And in my case I made sure to sand off an area of the strap between the poly cell (so cell makes direct grounding contact with the strap then where my grounding wire is attached between strap and frame was also a sanded area devoid of powder coating and then before filling the celI I tested the ground continuity.

It was a big deal, lots of research of rules, lots of tedious work, the work on paper before ordering anything was a key to a smooth result and a great new fuel system that in my case solved a long standing performance issue I had with the car prior...but that is a different story that is in my build thread.

Good luck on the work ahead.

[Cglrcng]

Yes, it ended up another novel. Sry.

[goinbroke2]

All good, thanks for the response! Two heads are better than one so I listen and learn from everyone. I have been avoiding the garage the last couple of days because I have so much other stuff going on. Have to put the tranny pan on and fill it..AGAIN and see if my latest "spring/valve/grinding slots/holes" recheck did anything. Not gonna lie, it's taken the wind out of my sails, so to speak. When I blew up the 3rd engine in 4 years, I parked it for 27 years. Not there yet but the "honeymoon" of having a stocker is quickly wearing off. I have another mustang (stock 86lx with 90,000km's original) that I have raced and could of bracket raced all summer, but I've been focused on the stocker and have been to the track once this year.

All that to say, I'll get back on it, but my motivation to hit the last race of the year in a couple weeks is waning.