Throttle body injection with Megasquirt

I'm working my way through wiring up a MegaSquirt unit to control throttle body injection on my ’65 E-pup with a 240 engine. I'll be using the distributor and Ford TFI ignition module that came on f150s with the 300 engine in the late 80s/early 90s and a Chevy TBI unit that was used on the 5.0/5.7 trucks from that period. I'm adapting a Megasquirt unit I built for another project a few years ago.

I've got most of the wiring done and I'm currently running lines for the high pressure fuel pump and fuel return.

An EFI system requires an amazing amount of wire to hook everything up, including fuses, relays, power and ground wires plus sensors and controllers. Sensors include air and water temp, wideband O2 and throttle position. Of course, I have to run wires for the two TBI injectors, plus idle air control, the new fuel pump and the TFI ignition module. Surprisingly, the only two wires I’m using from the original harness are ignition start and run that hook to the starter relay. Everything else is new.

Pics of progress so far:









I added a fuel return line bung to my tank. This is a 20 gallon Mustang tank modified for use in the Econoline.

Nice work, JD. Fuel injection does seem like a daunting amount work and tuning. But once it's all done you've really got something. There a guy, richcreations, on the fordsix forums that is going efi and low boost turbo on his econoline with a 200. He's using the ford 2-barrel cfi unit and Speeduino DIY ECU. I'm looking forward to see this all come together for you. Good luck!

Here's a short video showing startup of the MegaSquirt system on my Eco-Pup. I've been puzzling my way through this project for a few months now. I never worked very hard or long, and had to find and fix more than a few bugs. I was surprise how little documentation there was on Squirting the Ford TFI ignition system, so had to figure out a few things on my own. It's been quite a learning experience with a ton of reading.

I still have a lot of tuning to do, but at least it starts & runs!

Not used to seeing all those wires in one of these vans! Nice neat work, JD!

Nice Work.

In case anyone is crazy enough to try this, here's a wiring diagram:  

I went for a drive the other day in my MegaSquirted E-pup. It was running great at idle, but as soon as I started driving, things fell apart. EFI fuel systems don't like to suck air....  

One of the first things I did when I got the truck was install a 20 gallon Mustang fuel tank. Unfortunately, EFI wasn't on my radar back then and I went with an un-baffled tank suitable for a carb, but not EFI. I only had 2-3 gallons of gas in the truck and there was enough sloshing around that the fuel pump would suck air every time I put on the brakes or tried to accelerate. And the truck would stumble, snort and generally tell me it wasn't happy.

So, rather than replace the tank or try to weld on a sump of some sort, I decided to build a surge tank that will hold about 20 ounces of fuel, which will insure the high pressure fuel pump has plenty of fuel no matter how much the truck rocks back and forth.

The truck's stock, low pressure mechanical fuel pump will pump gas from the main tank to the surge tank. Then, an in-line high pressure pump will take gas from the surge tank and send it to the injectors.

Once the gas passes through the throttle body, a return line will run back to the surge tank, so both the stock pump and return will be providing fuel to the tank. Any overflow then goes back to the main tank via a third port at the top of the surge tank. Sounds complicated but really very simple.

I had already installed a high pressure in-line pump for the EFI system and had capped off the mechanical pump. So, it's been fairly easy to modify the system. I could have bought a surge tank of e-bay or elsewhere, but ended up making one out of a piece of 3" exhaust pipe and some odds and ends. The surge tank will mount under the bed next to the tranny and inline with the existing fuel lines.

Jdlaugh that is crazy that you just had that problem. I'm converting to direct port EFI and a turbo. I am also using the 20 gal mustang tank. I have been himing and hauing over my fuel pump choice for days now. I want to use an inline pump close to the tank. But I really like your set up. What psi and and flow rate are you using for your set up? I'm told I will need 180lph and 70 psi.

If you're using a unbaffled tank, you absolutely need either a sump or a surge tank. I had my high pressure pump mounted in front and slightly below the Mustang tank and it didn't work there once I started driving.

I'm using the Airtex E2000, which was used on a lot of v8 Fords from the mid 80s to mid 90s. It's rated for 150 lph/40 gph at a max pressure of 95 psi -- but I don't expect to get over 200 hp out of my old six.

Nice that surge tank doesn't look like to crazy of an option. Obviously your mechanical fuel pump is enough to flow those numbers? Is it just a stock fuel pump? Does anyone for that matter know what the flow rate for a stock mechanical fuel pump on a 300 will flow?

The replacement fuel pump I bought at Autozone for my 240 claimed 40 gph at 5 psi. If that doesn't seem enough you could install a low-pressure electric pump to feed the surge tank. You can get those for carbed applications that flow huge amounts.