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MG MGB Technical - SU fuel pump replacement points

Hi all

I went though many threads regarding the SU fuel pump and figured that sticking to the original spec with new points was a reasonable option.
Now I do not want to fuel a new debate on this but would be interested in your comments and advice on 'the right source' for those points :

- The Roadster Factory has them available (SUAUB6106) @ $19.95 while some other vendors retail them at about half that price (did not check with BFS though). I have always been very satisfied with TRF (availability, friendly support, prices, parts quality etc) although they are a source mostly for non MG parts hence my being puzzled.

- what would be the right price and a good source for 'top quality' genuine points ?

Thanks in advance for any help

Gerard
G. B. P.

Hi, Gerard - Many of the older SU pumps used a single contact set of points, and for some reason these are often more expensive (and less reliable) than the double points for the later cars. I don't think that situation appies in your case, but, words to the wise....

Cheers - - Alec
Alec Darnall

Gerard - The points sold by Roadster Factory sound to be the same as the ones sold by Burlen Fuel and are a much superior product to the cheaper variety.

As long as the swamping resistor inside the coil housing is intact, the points should give you quite a few years of reliable service (some people have 40 years of service out of original pumps that use points). Unfortunately, the only way to tell if the internal swamping resistor is in good condition is to install the new points and run the pump with the end cover removed (you will need to clamp the pivot pin for the points in place so it doesn't work it's way out while the pump is running) and watch for arcing at the points. With an intact swamping resistor and either the original capacitor or diode in the pump, there should be very little arcing at the points (if you have to turn out the lights to see the arcing, you are in great shape). If however, you see a lot of arcing at the points, either the capacitor or diode or the swamping resistor is bad. The capacitor or diode are easy to replace to check if they are the problem, but the swamping resistor requires pressing the coil out of the housing and getting a substitute resistor (100 ohms) to replace the original nichrome wire resistor. This is best left to someone withe hte tools and knowledge to accomplish this or get a new pump. Good luck - Dave
David DuBois

Thank you both for your input !

A conclusion from my reading earlier threads on the matter actually was : A. replace the points with top quality ones 2. if any further problem arises get in touch with David DuBois !

Now I need help in defining exactly what I should buy to overhaul my set of points (my car is a 1969 model / AZX1307 fuel pump) :
is the 'rocker and blade assy' (pn AUB 6106, that superseded AUB6113) the correct one ?

Thank you very much in advance !

Gerard
G. B. P.

For those following this thread :
Answer is positive, AUB6106 is the correct set of points for an AZX1307 pump !
Gerard
G. B. P.

Hi all.

Contact points are a well explored science, and the best contacts have tips that are either solid precious metal, or at least heavily plated with them.
As usual, you tend to get what you pay for.

Many MG's have a built in contact distress indicator in the form of a radio with Medium Wave.
If you tune the radio to a quiet part of the band you will probably hear a slight crackle as the pumps' points open, if this crackle becomes prolonged and / or loud the points may be on the way out.

This method can also be used a 'raise the hood' warning, as a nearby thunderstorm will also produce distinctive crackling.

As a final bonus, this method can also be used to help identify poor connections.. with the 'load' switched on (ie the flickering lamp or whatever) waggle the wires and when you waggle the right bit the radio will crackle.

Don
Don

Don - An interesting way to troubleshoot points. By "medium wave", what frequencies are you refering to? Is that the standard AM frequencies of above that band" Cheers - Dave
David DuBois

Hi Dave.

Yes, I am referring to the AM band, frequency range approximately 500kHz to 1500kHz.

Don
Don

Thanks Don, That's one I am going to have to remember. Of course it doesn't help with all electronic pumps. Cheers - Dave
David DuBois

This thread was discussed between 14/07/2005 and 17/07/2005

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