EFI to carb help

[Jimbob911]

I built my MK II in 2002 with an EFI donor car. I'm replacing the old 5.0 with a carbureted 347. I know I've seen lists of tips on the conversion to carb, in particular the electrical side, some years ago but can't seem to find many of the old posts. Any tips for unearthing those old checklists? Thanks much for any help.

[Inman Lanier]

If you're worried about fuel capacity and that's why you're switching out - I would consider instead of a carb getting a modern day throttle body injector system. You already are halfway there with the OEM fuel tank and high pressure fuel system. You'll be much happier in the long run IMHO. Just get a single plane manifold because those EFI systems don't do as well on dual planes (metering not as good).

If switching, the main thing you need to do is get a proper regulator for your fuel system. I would consider keeping the return line in use; get a regulator that uses that feature. Fuel injected pumps are 'process cooled' - meaning the fuel runs through the pump cooling off - you need the good amount of flow to prevent the pump from burning up.

If you don't go that route, then you can simply get a different pickup for your fuel tank and an inline low pressure fuel pump. You can use the power that goes to your existing in-tank pump.

[Jimbob911]

If you're worried about fuel capacity and that's why you're switching out - I would consider instead of a carb getting a modern day throttle body injector system. You already are halfway there with the OEM fuel tank and high pressure fuel system. You'll be much happier in the long run IMHO. Just get a single plane manifold because those EFI systems don't do as well on dual planes (metering not as good).

If switching, the main thing you need to do is get a proper regulator for your fuel system. I would consider keeping the return line in use; get a regulator that uses that feature. Fuel injected pumps are 'process cooled' - meaning the fuel runs through the pump cooling off - you need the good amount of flow to prevent the pump from burning up.

If you don't go that route, then you can simply get a different pickup for your fuel tank and an inline low pressure fuel pump. You can use the power that goes to your existing in-tank pump.

Thanks for the info. The die is already cast as far as the carb setup goes... I've got a Blue Print 347 coming with the intake manifold and carb installed as part of the package. My main issue is how much of the stock EFI/PCM wiring to delete and if there are any land mines to be sure I leave alone.

[Ford & Jeep Fan]

Here is site that can quite helpful making you own ignition setup. https://www.gofastforless.com/ on the left you have a small menu and click on Better ignition for more information.

If I was going Carb I'd have No reason at all to use a ECM of any sort.

[Papa]

If going to a carb, here are some things to consider:

1. Proper fuel pump and regulator
2. Remove/cap return line
3. What coil/ignition setup are you going to switch to?
4. What will be feeding your gauges if they were fed by the ECU before?
5. Colling fan control - temperature switch

I assume you had a donor Mustang engine previously? My recommendation is to "keep it simple". The BPE 347 will only require ignition, coil, and possibly choke connections. Where those come from in a donor harness will be the trick if you plan to leave that harness in the car.

[maclonchas]

I did look for posts also on this subject when I was looking at a carb engine early on for the design phase and came to the conclusion that most of the wiring from the harness would be a nightmare to unpack and trace out. You are better off with the engine swap just purchasing a simple wire harness as others have suggested on this thread. Remember, with a carb simpler is better and if you decide to go EFI (FITECH, Holley, Pro Flo4, etc.) or even a Carb Cheater, the simple wiring harnesses will support the system fairly straight forward. The last point I would make is that with a pre-built simple use harness, you can trouble shoot a lot easier and remove that old wire from your car.

Cheers,
Bill