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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - FUEL PUMP CLICK CLICK

I have an electronic Su fuel pump. When I turn on the key, the pump clicks fast and as pressure builds up it will slow down.(Normal) It clicks about every 3 to 4 seconds with the key on and the engine not running. This seems like too much to me. I have a Judson with a Holly carb. The only thing I can think of is a leaky or bad needle and seat. This carb has been rebuilt not to long ago. Any idea's.
JEFF BECKER

normal, but I would check for fuel leaks at the bowl to carb body connections.
Paul Hanley

Jeff - You have mail. Dave
David DuBois

Hi, Jeff - I see Dave has sent you an eMail, and that probably has the answers you seek, but - just in case - here's a couple of points to ponder.

If there is a leak in the carbs, you can find it by letting the pump run for ten or fifteen minutes, and see if your Holley overflows. At the slow ticking rate you mention, it will take several minutes for the float bowl to become full, and seep out. If the system is not leaking somewhere, a tick rate of 18 - 20 seconds is about right.

More likely, however, is an internal leak within the pump body, probably the input valve that connects to the gasoline tank. It doesn't take much grit to hold this valves open slightly. In normal operation the pump diaphagm is pulled backwards by the coil, the points open, then a spring behind the diaphragm pushes it forward to pressurize the fuel system. As the fuel leaves the pressure chamber, either forward to the carbs, or leaking backward toward the tank, the diaphragm moves forward, the points make, and the cycle repeats.

The older SU's used a brass plate that could be resurfaced when worn, but the newer (?) ones use a plastic flap within a valve body, which is pretty much a throw-away when worn. The good news is that these valves are still available for replacement from several sources.

Best of luck - - Alec
Alec Darnall

I'm sorry but I have never heard of fitting a "HOLLY" carb to any MG (other than the Rover V8 MGB's). Webers yes but "HOLLIES" over my head.
Greg & Grimm
G.J. Cenzer

The Judson supercharger kit for the MGA came standard with a Holley carburetter.

http://www.infostuff.com/carstuff/mgacbc/mgajudson.htm
Jeff Schultz

Those were the days. $35 for installation including dyno testing.
Tom

This thread was discussed between 10/09/2005 and 12/09/2005

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