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 Posted: 10-07-2018 03:52 pm
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Esprit2

 

Joined: 05-01-2005
Location: Minneapolis, Minnesota USA
Posts: 575
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The attached photo shows the fuel restrictor... for what that's worth.

In effect, the restrictor is just a 'dumb', non-adjustable pressure regulator. So an alternative is to install an inline, adjustable fuel pressure regulator. Just delete the T-fitting in the fuel pump outlet hose to the carbs, and its return hose to the tank. That return line is where the restrictor would normally be. Then install the adjustable pressure regulator as close to the carb inlets as practical, and set it to 2.0 to 2.5 psi. That's what I run in my Britcars that have electric pumps.

The fuel pump is usually mounted lower than the carbs, and way in the back of the car. With 4 psi at the pump outlet, flow loss plus some drop due to elevaton change will normally result is something less than 4 psi at the carb inlets. When diagnosing fuel system problems, measure the pressure at the carb inlets. That's what counts.

As long as the carb's floats and inlet shut-off valve are working well, a slightly high pressure shouldn't be a problem. However, as they age and become less effective, excess pressure over 2.5 psi can result in an overall rich condition.

Regards,
Tim Engel

Attachment: Fuel System - Return Line Restrictor 0.046 Inch ID.jpg (Downloaded 124 times)

Last edited on 10-07-2018 03:58 pm by Esprit2