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MG MGB Technical - Fuel Pump Problem

The fuel pump on my 1979 B has stopped ticking when I turn the igniton switch. The battery is fully charged but the engine will not turn and fire. I have tried tapping the fuel pump in the boot with no success. I checked to see if power was at the pump and it is present. My next thought was removing the cover on the pump and replacing or cleaning the points. How are the points accessed ? The pump is marked AUTO PUMP, mfg in NZ, part # AP115.

Any help would be gratfully appreciated.

Cheers, Davy Crocker
Davy Crocker

Since you don't have an SU pump it probably isn't servicable. Dave DuBois will probably respond, he will know if your pump can be repaired.

Clifton
Clifton Gordon

Davy - The Auto pump doesn't have any points, it uses a magnetic reed switch to trigger the pump's operation. It is a good pump while it is working, but unfortunately it is not servicable, so you are looking at getting a new pump.
Cheers,
David DuBois

Hold on a bit, he says that as well as no ticking when he turns on the ignition, neither will the engine 'turn and fire'.

Even if the description is incorrect, and it *is* cranking but not catching, then I'd still expect the engine to fire and run for a short period while it uses the fuel that remained in the carbs from the last run. Assuming it was running in the near past.

If the engine isn't even cranking on the key then you are looking at a major electrical fault that replacing the pump won't fix. Does the ignition warning light come on when you turn the ignition on? Do the lights work? When you turn the key to crank do they stay lit or go out. Of course it is quite possible that you have two faults - one of them being the fuel pump, but I'd find out what is stopping the cranking before changing the pump. Even *then* you should be tracing the 12v and ground supplies all the way to the pump to make sure it isn't a bad connection somewhere.

Just because the pump no longer ticks, it doesn't meant it has to be the pump that is faulty.
Paul Hunt 2

Good catch Paul (I shouldn't send answers after midnight). If, after following Paul's advice, you find that there is power to the pump (you should also check that the ground wire is in good order) and it is still not ticking, then replacement is in order. Cheers - Dave
David DuBois

Gentleman, I do have lights all around and I do have 12 volts at the pump. The engine still does not fire. I drove 50 miles , four days ago and the non starting condition appear the day after. I replace the female connector on the ground wire and sandpapered the area where the ground wire connects to the body. I also checked and the gas gague indicates that the gas tank is above 1/3 full. At first, I tried jump starting with no positive results, but then found that the battery has a full charge. It looks like a replacement is in order.

Thanks for all of your help. Cheers, Davy
Davy Crocker

Davy - One further item to check before you condem the pump. Remove both lines from the pump(remove the fitting at the tank first to prevent the open end at the fuel pump from syphoning fuel from the tank) and then see if the pump will run. If it does, there is a clog in one of those lines. If it still doesn't run, then the pump is bad. Cheers - Dave
David DuBois

Gentleman, I took Paul's advice and dug deeper into the problem. After removing the boot that covers the starter, I gave the solinoid a tap with an "Irish Wrench". Thunder storms were approaching, so I quickly turned the ignition key and the car started.

Thanks again for all of the advice. "Every MG problem has turned into a wonderful learning experience".

Cheers, Davy Crocker
Davy Crocker

This thread was discussed between 04/07/2007 and 06/07/2007

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