The Summer of Ven: Reassembling the IDI Electric Fuel Pump System

Last time I ripped most of the OEM fuel system out of the engine cave on Spool Bus, and received the parts needed to fabricate the new fuel system. So here’s where I get to put it all back together!

First things first, the new Facet e-pump itself has to be mounted. I chose to put it on the frame, right next to the filter head that some previous owner added. If you wanted something comprehensive, it seems like the R&D frame-mounted filter and pump kit is the go-to. But I already had the hard part done for me, so might as well use it!

And here it is all mounted up. At this point the fittings were just threaded in for visual effect – after I installed everything I realized some of them had to change.

So here’s what’s going on now with the plumbing. The long arc at the top is the inlet coming from the fuel tank selector valve. The fuel gathers at the clear strainer (so I can see how much poo is in it) and is sent to the filter head, then from there, to the rest of the fuel system.

This is what it looks like on the inside. It passes through the frame at two pre-existing holes – I suspect the filter head location was chosen by a P/O for this convenience. For completion’s sake it needs a plastic grommet here at the holes, which I ordered but wasn’t here yet (BURNOUTS NOW, GOOD IDEAS LATER)

With the system plumbed up to the filter outlet, time to test everything and give it its first powered break-in!

The magic van juice flows. The Facet pump makes a pretty loud clicking sound as it’s operating, possibly indicative of it being a vane type pump instead of a small centrifugal or axial flow turbine like most in-tank pumps that make a more whirring or buzzing sound.

I had this setup hilariously looping back on itself (hose back into the fuel tank) for about 5 minutes or so to break the pump in.

The remaining plumbing steps were all engine-side. I needed to cut the existing injection pump feeder line that went to the OEM filter housing and turn it into a fitting I could attach to the fuel hose, then add a return system.

Getting to the injection pump inlet fitting was, how should we say, unpleasant. Again, no overhead view, so this was done with a phone camera inspection video and then by feel. First, I had to remove the intake plenum thing to get access to the injection pump’s backside, which was an easy enough operation (though I had to loose and shift, but not remove, the turbo). There’s only space to turn the wrench 1 hexagon side at a time.

And here it is, the original filter to injection pump line.

I used a tube flaring tool from Harbor Freight to cut, then form, then put a gentle flare onto the end of the rigid line. It’s supposed to stick up just a little out of the center valley so I can slide the rubber fuel hose over it.

If taking the fitting off was a lengthy video game side quest, then re-mounting it was some kind of next level miniboss that didn’t even drop goodies. I had to do most of the initial mating and threading by hand.

The updated feeder line terminates in this photo just under the rubber vacuum hose to the right.

Here’s a new front-towards-back view of the now much more spacious engine cave.

The original fuel feeder line coming from the selector valve was wrapped around under the front of the engine, rising upwards on its forward passenger side face. I gently bent the rigid line where it began on the frame to point towards the back of the engine. Again, slightly badly lit photo, but you can see the “Nipple to Nowhere” pointing downwards in the center, which is where I’ll attach the new fuel line.

While doing this, even more parts had been arriving. A new expandable intake hose, for one, but more importantly, I received the electric solenoid valve and fittings for making a device I nicknamed the Dongle of Diesel Distribution:

So here’s what’s going on. The DDD takes in fuel from the pump/filter on the bottom left fitting. The electric solenoid is connected vertically above it, in order to give a high point for air to collect. It then does a U-turn while touching a pressure sensor, and the injector pump hooks in on the rightmost fitting. The top “exhaust” fitting will be routed into the fuel return lines.

I decided it’ll mount right here, at the studs where the former OEM filter housing was located.

I decided to get silly and design up a snail-shaped mount to be 3D printed. Bent piece of sheet metal? Sure, why not. But that wasn’t extra.

Whatever, it’s a snail if you squint hard enough.

It’ll be made on one of my Markforged machines from their carbon fiber nylon composite material, Onyx. My favorite vegetable for making dishes as diverse as entire beetleweights to welding fixtures to …. stuff like this.

I actually modeled this up and had it running on the printer while I was doing the plumbing work that night, so it was ready by the morning!

The finished snail bracket assembly! The only place to “mount” this so to speak was using the solenoid valve’s mounting holes.

I grab one of the studs of the former OEM filter mount to locate this thing, and also function as a ground point for the solenoid valve.

Am I confident that the print will survive underhood temperatures? Absolutely. Hell, just about everything in a new car is made of fiber-filled Nylon of some sort… to my chagrin.

Time to do some final plumbing. I’ve linked up the injection pump (hose labeled -> IP ->) and the feeder line, and the free hanging one will be the return vent line.

For fuel pump power, I fished up a long 16 gauge wire following existing brake lines to meet the repurposed fuel heater power drop.

Here’s what’s going on underneath. The orange and black bundle going off to the right is the fuel pump power.

The DDD purge solenoid is grounded on the OEM filter mount stud and I ran a purple wire up and over the engine cave (note the orange and purple wires in the wiring tray at the top) to meet the solenoid wire.

I connected the solenoid wire to a 12V access point at the Centurion-supplied fuse block. Then I pulled the doubled-up wire into the cabin via the same terrible, un-insulated, un-grommeted hole everyone else has been using (“Not the better redneck, just the most recent”) and the cut the doubled up loop. Now I just need to connect the ends to a switch to enable the solenoid.

A photo of the Wiring Teratoma now with my own additions (blue overdrive connection, purple purge solenoid….)

I found a button switch in one of my Collections and decided to just position it above the fuel selector switch. It’s a momentary button, so if I ever do some kind of service on the fuel system that empties it out, I’d just key ON (not start) and hold the button a few seconds to let the system quickly prime.

To be fair, once you have an e-pump, it will eventually shove all the air out of the system anyway, save for any air that might be trapped in the injection lines themselves which will need to be individually bled at the injector (no thanks) or cycled out through brute force.

On the reassembly path some more! Here’s the back side of the intake reassembled with the new extend-o-hose, now free to run diagonally across the engine cave without tripping on ANYTHING.

The “Cold” “Air” “Intake” is now back in place as well. That’s really all there is to it for this install.

And now we’re ready to fire back up. Verdict? Well, it works the way it’s supposed to. If I push the purge button, fuel begins blasting out of the return tee junction instead (oops, forgot to tighten that clamp). However, now that the system is being consistently pressurized to 10 PSI, I’m watching ALL of the injector return fittings spew diesel fuel every time the pump is running.

Welp. That’s what the next post in this series will cover: all the collateral damage, including repair of the return lines and fittings. While I waited on these parts, I also decided to get new glow plugs and repair that circuit.