Alfa Romeo Owners Club of Australia Forum

Technical => 105/115 Series (105 Coupe/Spider/Berlina) => Topic started by: 1750GTV on March 30, 2018, 02:22:54 PM

Title: Electric fuel pump
Post by: 1750GTV on March 30, 2018, 02:22:54 PM
The mechanical fuel pump on my 105GTV has given up the ghost and I was thinking of replacing it with an electric pump.
I've searched the posts and can't find much so I thought I'd ask.

So -
Has anyone done this and what problems did you have?
Is one brand better than any other? I have a Facet one in my Giulietta Spider which does the job well.
Where do I mount it? I'm assuming somewhere high up in the diff/rear axle well.

The electrics shouldn't be a problem. I can run a switched and fused lead from the back of the ignition barrel.
I can get a blanking plate for the old mechanical pump from the o/s suppliers.

The car is a 1750 with standard twin 40DCOE Webers.

Any help is appreciated,
Chris
Title: Re: Electric fuel pump
Post by: LaStregaNera on April 03, 2018, 09:44:08 AM
From memory, the GTA fitment was a pair of Facet reds mounted vertically on the back side of the vertical panel Infront of the axle/under the front of the back seat on the driver's side. I assume having two was incase one failed, because one is more than enough pump. There's nothing to be really gained on a street car with going to an electric pump other than and another noise to listen to...
Title: Re: Electric fuel pump
Post by: Citroënbender on April 03, 2018, 11:03:47 AM
I’m a big believer in electric fuel pumps.

Fitted with a separate fused supply (via relay) and either tacho, inertia or oil pressure safety switch, they provide instant, dependable fuel feed. The ability to incorporate an immobiliser is also nice.
Title: Re: Electric fuel pump
Post by: 1750GTV on April 05, 2018, 07:32:20 PM
Thanks for the advice.

I'll get the car up on the hoist on the weekend and have a look at potential mounting points.

Chris
Title: Re: Electric fuel pump
Post by: bonno on April 05, 2018, 09:19:58 PM
Hi 1750GTV
Apart from CB’s essential requirement for having a fail safe shut off device, several other points to consider when converting from mechanical to electric fuel pump,
•   coversion kits are available on e-bay.
•   incorporate fuel filter between pump and tank
•   incorporate pressure regulator
•   pressure gauge (desirable).
Information on wiring diagrams and how to convert is available on the internet.
Title: Re: Electric fuel pump
Post by: carlo rossi on April 06, 2018, 11:06:03 AM
i Believe you only want around 3psi pressure
most are around 10psi and they cause the needle and seat to stay open
Title: Re: Electric fuel pump
Post by: LaStregaNera on April 06, 2018, 11:58:58 AM
i Believe you only want around 3psi pressure
most are around 10psi and they cause the needle and seat to stay open
That's why you feed through the factory filter/regulator in the engine bay.
Title: Re: Electric fuel pump
Post by: Citroënbender on April 14, 2018, 08:18:57 PM
The NZ company called FuelFlow make some low pressure non-serviceable pumps. Their 015 or 020 pumps would be a good starting point.

Use of a return style pressure regulator avoids the risks of "deadheading" the pump.  The main issues here, are pressure creep up to a level that forces a needle off its seat, flooding the carb, and simply overtaxing the pump (a bigger issue with the meaty electric pumps like Holley Blues, where the motor can damage itself due to available torque).  Bundy tube is readily available off the roll for making discreet and safe return line runs. 
Title: Re: Electric fuel pump
Post by: Gary Pearce on April 15, 2018, 05:28:50 PM
I wouldn't do it. The original mechanical pump is reliable, quiet and inexpensive.
Unless you are racing with bigger carbs the electric noise will drive you crazy. Keep it original.

Title: Re: Electric fuel pump
Post by: 1750GTV on April 16, 2018, 07:46:57 PM
Thanks to all for your useful comments.

Still weighing it up and I may end up just replacing the original 48yo mechanical pump.

Chris
Title: Re: Electric fuel pump
Post by: gebe1 on May 19, 2018, 10:46:32 AM
Hi Chris,
I agree with Gary. Keep it original. I have a 73 spider and when i got it , it had an electric fuel pump. I quickly removed it and it was the smartest thing I did. Not only was it noisy, but, it was unnecessary, as the original pump was solid reliable and no issues.
Title: Re: Electric fuel pump
Post by: 1750GTV on May 19, 2018, 07:45:26 PM
Thanks gentlemen.

I've replaced the pump with a new mechanical one.

Chris