MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

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 MGB Technical - SU fuel pump

Cars been sitting for a while. fuel pump worked really well with a smack for a while. Anyway, I took it out and cleaned the points in it and now it won't shut off. I didn't think the points would have anything to do with the pump quiting to run after pressure was reached in the line, and also I only removed and replaced the two connectors at the pump, so I can't see how that would affect it. Just strange and thought maybe someone had an idea.

Thanks,
John
John A

When I replaced my SU with an electronic pump I found that wouldn't shut off either. When I disconnected the pipe at the carb. end of the line to check if fuel was actually flowing, the air trapped in the pipe escaped and when reconnected the pump clicked twice then shut off. Been going fine ever since.

HTH
Vic
V Todman

John - Try removing and reconnecting the inlet and out let lines from your pump and retry it. Probably you have something loose on the inlet side of the pump causing it to suck air into the pump. For more information about SU fuel pumps and a write up of my SU fuel pump services go to the following web site: http://www.custompistols.com/cars/articles/dd_su_fuel_pumps_101.htm
Good luck - Dave
David DuBois

Check the in-out valves.

They're a reed type and use a very thin plastic,
and they tend to tear and crack when they're
about to go out.
Daniel Wong

John you might have bent the points a little. YOu will probably have to reset the wind in on the diaphram spindle. If I recollect correctly, you need to wind the diaphram in until it won't kick over at all and then out a couple of bolt holes (20 dgrees).
Peter

Peter is partially correct in describing how to install
a new pump diaphragm.

Be sure to adjust the points gap before doing this.

Then:

1) Screw the diaphragm in while pressing it
in & out until the points stop ticking over.

2) Unscrew the diaphragm slowly until the points
just begin to tick over, again.

3) Unscrew the diaphragm 4 more bolt holes.

Daniel Wong

This thread was discussed between 18/09/2003 and 20/09/2003

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.