Electrical fuel pump

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nibbes123
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Your car is a: 1979 Fiat 2000
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Electrical fuel pump

Post by nibbes123 »

Need some advice on hooking up an electric fuel pump from the tank to engine, car is a 1978 with a 2litre engine. Also will a after market pump work and what psi does the pump need. car is carbed with a 32/36 DFEV.
thanks
Nick
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kmead
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Re: Electrical fuel pump

Post by kmead »

A carb needs 2-4 lbs of pressure. An electric fuel pump needs to be near the tank as they tend to push rather than pull. I would put it as low as possible, the front right corner of the tank to the right of the line outlets next to the spare is a pretty protected spot and the pump won't need to pull the fuel up very far.

When wiring it up you need to make sure it only runs when the engine is running in case of a crash so it doesn't keep pumping fuel through a ruptured line.

Personally I would stay with a mechanical pump. It only runs when the engine is turning, the means of running it are already there (less work) and you don't need to run wiring. A mechanical pump can supply a single or dual carb with no problem. I have OE pumps on my cars and have never had a fuel delivery issue.

An electric fuel pump is a great thing but its not really needed.
Karl

1969 Fiat 850 Sports Coupe
1970 Fiat 124 Sports Coupe
1985 Bertone X1/9
nibbes123
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Re: Electrical fuel pump

Post by nibbes123 »

Hi kmead

The reason I am going with a electrical fuel pump is be cause I have a 2litre block that came off a 1982 spyder FI , so the opening for the pump is closed. Would you be able to tell me where I could wire the pump to so when the engine is not running it also is not.
Thanks
Nick
Fiat88

Re: Electrical fuel pump

Post by Fiat88 »

nibbes123 wrote:Hi kmead

The reason I am going with a electrical fuel pump is be cause I have a 2litre block that came off a 1982 spyder FI , so the opening for the pump is closed. Would you be able to tell me where I could wire the pump to so when the engine is not running it also is not.
Thanks
Nick
The way the PO on my car hooked up the electric pump is when I turn the key the pump comes on, not when the engine is running, not so safe it seems crash wise. :shock: I also would like to know how to wire it up properly? :D
nibbes123
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Re: Electrical fuel pump

Post by nibbes123 »

Need to know if I need a fuel regulator if Iam running a pump with 2-4psi for a carb set up.
Fiat88

Re: Electrical fuel pump

Post by Fiat88 »

Fiat88 wrote:
nibbes123 wrote:Hi kmead

The reason I am going with a electrical fuel pump is be cause I have a 2litre block that came off a 1982 spyder FI , so the opening for the pump is closed. Would you be able to tell me where I could wire the pump to so when the engine is not running it also is not.
Thanks
Nick
The way the PO on my car hooked up the electric pump is when I turn the key the pump comes on, not when the engine is running, not so safe it seems crash wise. :shock: I also would like to know how to wire it up properly? :D
Anyone have wiring instructions to hook it up like that? Thx.
rlux4
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Re: Electrical fuel pump

Post by rlux4 »

Back in the day one of Fiats reputations was engine bay fires, so an electric fuel pump that shuts off when the engine stops is a good idea in my mind.
How about voltage coming off the alternator, it would stop if the engine wasn't running.
I'm not an automotive electrician, so if my suggestion won't work, hopefully someone with more knowledge about it will chime in and educate us.
Ron
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BEEK
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Re: Electrical fuel pump

Post by BEEK »

use a relay, switched by the oil pressure "idiot light" sending unit. when the motor has oil pressure the fuel pump runs, when the pressure goes below 5psi it shuts off. good for 2 reasons. if you loose oil pressure the fuel supply will quit, keeping you from ruining your motor. secondly if in a bad accident the motor stalls, the fuel pump will also shut off.
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
james124

Re: Electrical fuel pump

Post by james124 »

You may need to get a fuel pump relay kit similar to this
http://cgi.ebay.com/ebaymotors/new-Aero ... 3a4b198480

Don't know if this has the low oil pressure shut-off feature that's been suggested. Good Luck, James
BEEK
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Re: Electrical fuel pump

Post by BEEK »

james124 wrote:You may need to get a fuel pump relay kit similar to this
http://cgi.ebay.com/ebaymotors/new-Aero ... 3a4b198480

Don't know if this has the low oil pressure shut-off feature that's been suggested. Good Luck, James
yes this will work, but please dont pay 75.00 for a 10.00 relay
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
Fiat88

Re: Electrical fuel pump

Post by Fiat88 »

BEEK wrote:
james124 wrote:You may need to get a fuel pump relay kit similar to this
http://cgi.ebay.com/ebaymotors/new-Aero ... 3a4b198480

Don't know if this has the low oil pressure shut-off feature that's been suggested. Good Luck, James
yes this will work, but please dont pay 75.00 for a 10.00 relay
Thanks for link and ideas. Good news is I have most of that stuff already in my garage. Just need to buy a 12 V, 30 amp circuit breaker or can I use a 30 amp inline fuse instead?

Might need some clarification on how to hook up the relay, though.
BEEK
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Re: Electrical fuel pump

Post by BEEK »

15 amp should be plenty. i will draw a diagram and photograph it and post it, if no one does it first
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
Fiat88

Re: Electrical fuel pump

Post by Fiat88 »

BEEK wrote:15 amp should be plenty. i will draw a diagram and photograph it and post it, if no one does it first
That would be great and much appreciated! :)
Fiat88

Re: Electrical fuel pump

Post by Fiat88 »

Was looking around on the web and found this painless wiring kit. You guys think its worth the price? http://www.shopatron.com/products/produ ... .0.0?pp=8&
baltobernie
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Re: Electrical fuel pump

Post by baltobernie »

No, I don't. This is worth the price http://www.amazon.com/Tyco-Relay-SPDT-F ... B000P61E36
his p/n is also suitable for headlight improvement.

If you insert a relay into the fuel pump circuit, you'll need to find a way to let the pump run from cold, before the engine develops oil pressure, so that you can start the car. A time-delay relay would work, but they are expensive, and another electrical item to troubleshoot if there's a problem. I decided not to relay my new installation, and run the fuel pump directly from the ignition. I suppose for safety's sake, I could insert an impact switch into the circuit (like modern cars) to interrupt the voltage if there's a crash.
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