• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

RUSTY FUEL PUMP

Share this page

1979Roadster

1979Roadster

Freshman Member
Offline
HI ALL, I just recieved a used fuel pump for my 79. My original is rusty as the sun is yellow/orange. I applied power to the used one and nothing happened. I unscrewed the cover for the points ( I never knew fuel pumps had points) and they looked pretty bad. Is it possible to burnish and clean the points or should I just replace them? I want to make sure it works. also on the top and bottom it looks like they have round vents. Should there be hoses hooked up to them, or do they draw air to the pump just the way they are? I have a service manual, but it doesn't say anything about them.
Thanks in advance to all replies.
 
If I were you, I would replace the points. The little vents are to relieve air behind the diaphragm and usually have a small hose that vents into the trunk where the end is out of the dirt and water spray from the road. PJ
 
THANKS PJ, I am going to get a new pump from Pierce Manifolds. I found in the archives "genuine" metallic square facet fuel pump for about $40. I understand they work well. I appreciate the info, sorta new to MGB's. This one has been sitting for 17 years, so.......
replacing the rubber in the cylinders right now as well.
regards
 
I don't know what pressure the facet pumps put out but, about 2 to 3 pounds of pressure is all most "B" carbs can take. 17 years, yup, we all know what your going through. I know it's hard but, try not to get in too big of a hurry to get it on the road. Enjoy the rebuilding process. If frustrated, walk away. The rewards are many when it's done. Good luck! PJ
 
SU points are easily cleaned and the "throwover" position reset. Forget the Facet. Might want to inspect/replace the diaphragm. SU pumps last a long, LONG time.

Tickticktickticktick, tickticktick, ticktick, ti.............ck.
 
Paul is correct, replacing the points is the best approach for a pump with burned points. However, there are other considerations that have to be figured into the equation. If the points are badly burned, two seperate conditions may be the cause. First, the pump may have reached the point of needing a complete restoration, complete with a new diaphragm. The other condition that may exist is that the pump was stalled in a current on condition at some time and burned out the internal swamping resistor. If this has happened, the arc suppression circuit is no longer able to keep excessive arcing from occuring at the points and they burned out prematurely. In this case, replacing the points will only result in the new points burning out in a short period of time. I have noted over the years, that this second situation is rather common in the AUF 300/AZX 1300 series pumps used in the MGBs. If you want to try relacing the points, e-mail me and I'll send you a set of instructions for correct reassembly and adjustment of the pump.

The little square, run all the time, make a lot of noise, Facet pump is a good pump that will last about as long as the SU pumps, but its noise will drive you crazy if it is not sound mounted. The newer Facet pumps that are epoxy enclosed are a bit quieter. Ask for the low pressure pump that has an outlet pressure of 2.5 - 4 psi to use on the MGBs.

The vent tube at the bottom of the coil housing is the one that neds to be run into the trunk or other high area under the car, to avoid getting water sucked into the pumps interior when driving in rain or other wet road situations. The vent on the end cover has a check valve in it and doesn't pull outside air into that area. Additionally in hte 79 MGB, the end cover prodrudes into the trunk area where there is relatively dry air.

If you are not comfortable tearing into the pump yourself and wan to have it restored, see my article of fuel delivery troubleshooting for a list of people who do work on SU fuel pumps at: https://www.svmgcc.org/tech_tips/fuel_delivery.htm
Cheers,
 
DAVID, THE ONE I BOUGHT ON EBAY I GOT TO WORK. TORE IT APART AND CLEANED THE POINTS WITH A BURNISHING TOOL AND SOLUTION. SO THE REPLACEMENT WORKS GREAT. DID THE SAME TO THE RUSTY ORIGINAL, BUT IT DIDN'T WORK. GONNA PUT TBAT ONE ON EBAY. I AM SURE IT IS REBUILDABLE. THE FIXED PUMP WORKED GREAT, BUT THEN I FOUND I HAD A LEAK IN THE LINE TO THE FRONT ABOUT 2 INCHES OUT OF THE BANJO FITTING. ONE THING OR THE OTHER I GUESS.
I APPRECIATE THE ADVICE.

GOT A NEW POST ABOUT THE HEADLIGHT SWITCH. I CANNOT TURN THE HEADLIGHTS OFF IN ANY POSITION.
 
Back
Top