1973 Mustang Returning to Carburetor from a EFI

258 Views 4 Replies 2 Participants Last post by Gazzotte, 4 d ago

Gazzotte

Discussion Starter · 9 d ago

My recently acquired 1973 Mustang with 351C 4v stroker kit to 408 with Fitech EFI I don’t care for EFI on an older car and return to Carburetor with that said what is all I need to make the conversion? Currently electric in tank fuel pump, so a pressure regulator, what is a good one? Do I need a new distributor? do I replace the intake manifold? Anything else? Thank you

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PSIG

· #2 · 9 d ago (Edited)

Typically:

remove FiTech throttle body and harness
replace sending unit with stock unit
reconnect fuel line to stock mechanical pump with filter
install carburetor
unlock and reconnect distributor to stock-type coil (if changed) -or-
replace distributor and coil with your choice
tune carb and ignition properly
sell FiTech unit to me

This sets everything back to stock or the configuration you want. This assumes the PO did not make weird changes in any previous modifications.

If you have an issue with the FiTech, I would have someone knowledgeable have a look at it. If it works fine but EFI just makes your skin crawl, retrofitting is a couple hours, plus tuning. Do your thing!

[EDIT] The better option to using a high-pressure pump with a new low-pressure regulator is reverting to the stock pump and no required regulator. Simpler, cheaper, more stable for the carb. You wouldn't volunteer to adapt a blowtorch to light candles, and this is similar.

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Gazzotte

Discussion Starter · #3 · 5 d ago

Thank you PSIG, question, if I use a mechanical fuel pump and just disconnect the power to the intank fuel pump will that work? ( I really don’t have a way to remove my fuel tank in my garage. Thank you

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PSIG

· #4 · 4 d ago

The in-tank pump may have a strong check valve. I would test it by disconnecting the fuel line and see if you can get free-flow through the line with gravity drain or mild suction. If not, then the pump must come out, or use it as a lift or feeder pump with a low-pressure regulator. Not suggested, more expensive, and more prone to failure if sucking air for a carb (or less usable fuel in the tank), but may have to be the path if the check valve is too restrictive and you can't get it out. 🤷‍♂️

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Gazzotte

Discussion Starter · #5 · 4 d ago

PSIG said:
The in-tank pump may have a strong check valve. I would test it by disconnecting the fuel line and see if you can get free-flow through the line with gravity drain or mild suction. If not, then the pump must come out, or use it as a lift or feeder pump with a low-pressure regulator. Not suggested, more expensive, and more prone to failure if sucking air for a carb (or less usable fuel in the tank), but may have to be the path if the check valve is too restrictive and you can't get it out. 🤷‍♂️

Thank you PSIG I will test it out before I take things apart

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