Thread: Electric Fuel Pump

Most carburettors won't handle more than about 4.5psi and from playing with other types of Webers in the past they were quite sensitive to too much pressure. I used to use a pressure regulator with the side and downdraft ones and limited it to about 4psi. The needle and float can be overpowered and cause the carbie to flood with too much pressure while less pressure is fine as long as the flow is there.

The standard mechanical fuel pump will work with the Weber and I have used a Facet with the Zenith in the past.

Cheers,

TimJ.

G'day All,
Agree with Timj comments. I run a standard mechanical fuel pump on my 2.25Ltr petrol with Solex carb and have a permanent fuel pressure gauge fitted and reads 4 PSI at the output of the pump with 5/16" fuel line hose. Hope this helps.
Chris

Originally Posted by Timj

I used to use a pressure regulator with the side and downdraft ones and limited it to about 4psi. Cheers,TimJ.

Hello Tim,

Could you please let me know the details of the pressure regulator that you used? Also, where in the fuel delivery system did you fit it? Thank you.

Kind Regards
Lionel

Hi Lionel,

This was on a Mazda Rotary with a 48IDA downdraft Weber and it was just one that could be bought from the local auto parts shop at the time, along with the glass inline fuel filters. It was basically the last thing before the carbie but from memory was mounted on the firewall. It was metal with a dial type adjustment on the top to set the required pressure.

Here's one similar - Weber Performance Carburettors

Cheers,

TimJ.

I heard back from Weber who say the Weber Carbs are designed to work at 3.5psi . 4.5 psi tops, no more.


cheers,
D

use the 3.5 psi or lower, I found that using anymore and over corrugates and general off roading the extra psi would cause the float to "stutter" and flood the carby.
Cheers Scott

Originally Posted by Timj

Hi Lionel,

This was on a Mazda Rotary with a 48IDA downdraft Weber and it was just one that could be bought from the local auto parts shop at the time, along with the glass inline fuel filters. It was basically the last thing before the carbie but from memory was mounted on the firewall. It was metal with a dial type adjustment on the top to set the required pressure.

Here's one similar - Weber Performance Carburettors

Cheers,

TimJ.

G'day Tim,

Been a while since your reply and I just thought of another question. Does this fuel pressure regulator need a bypass - return line back to the fuel tank? Or does it just handle the pressure happily as the electric fuel pump keeps delivering the fuel?

Kind Regards
Lionel

Lionel,
It handles the back pressure from the pump.

Below is a picture of my Series I which has two tanks, both Facets are plumbed into a pressure regulator.



Previous owner had been running without a regulator but we found the Holden carby wasn't happy. Father-in-Law took the regulator off a Motorkana car he was scrapping, a few pneumatic fittings, some PTFE tape and all fixed. The non-return valve in one of the Facets isn't sealing so as I drive on one tank the motor runs & it slowly tops up the second tank (must get round to fixing that one day !).


Colin