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MG MGB Technical - SU electronic pump

Hi. Mine is an MGA, but I have an MGB style pump I refurbed a while back, now acting up first thing on starting.
I'm looking at replacing it with the same style (Ports on the side) ASX1307EN.
This has the electronic switching vs the points.
Any feedback on experience with this pump feeding SU's?

Art Pearse

AZX1307 is the standard pump for MGBs at least. EN indicates it is for negative earth, EP for positive earth. They are also listed 'Electronic', i.e. NOT points, which is why there are separate polarities. The points style are AZX1307 or AZX1308. They also used to be polarity specific, hence the two numbers, but are dual polarity again.

But if you have a points-style now it's worth having a look at the points and checking they aren't spiked and pitted, which causes them to stick operated when you turn on the ignition (one click each time), or burnt or worn which results in no click. Cleaned and refaced, and checking the released and operated clearances, may be enough to fix it - worked for me with a similar problem.
Paul Hunt

Hi Paul. Trouble is, in the MGA, the pump is in a horrible place to do things like clean points, so I thought the EN type would be more reliable.
Art Pearse

Regular use and the points won't need cleaning! With points the pump can be "encouraged" with a sharp tap. With electronic if it stops, it stays stopped. My points type lasted for 10+ years (since before I had the car). It wouldn't start one time without the tap, which alerted me to the need to investigate.

In the UK there are German made SU look alikes that seem to be quite problematic. (Cheaper than SU)
Michael Beswick

Art - The points style pump will always require dressing the points periodically regardless of how well the pump works. The arcing at the points as they open and close will eventually wear the contacts unevenly to the point that they will need to be filed so that they make a good contact. the second problem is the contacts developing a film that insulates the contacts from one another over time (this is worse if the car is not driven on a regular basis). These two situations are present with just about any type of a points driven situation and the only way to get away is to go to the all electronic pump or to my optical trigger.

The easiest way would be to purchase one of the all electronic pumps. These work well and I have not come across any that have worn out over the years. The only problem that I have come across is that they have often come from the box with a maladjusted alignment of the magnet that triggers the circuit that usually doesn't show up until the pump has been installed and is working under load. This situation is easily corrected by readjusting the positioning of the magnet that triggers the circuit. If this problem arises, I can give you instructions on how to make the adjustment.

The other alternative would be to send your existing pump to me and I will restore the pump and convert it to my optical trigger system. The problem with this approach is that I shut down at the end of May (so I can work on the ever present 'honey do' list during the summer months). This means that I would have to have the pump as soon as possible so I could complete the work on the pump. Which ever way you choose to go, you can contact me at Cheers - Dave
DW DuBois

I have 2 V8's, both pumped by SU's. One, the electronic one, is 12 years old, the points version is only 2 years old. No problems with either.
Allan Reeling

Art, if you are going to get your old pump updated, Dave is the man to see. If you decide to purchase a new, all electronic pump, the SU fully electric version is extremely dependable. Mine has been in service for over 12 years now with no problems whatsoever. RAY
rjm RAY

Ray, good to hear! I just laid out for the AZX1307EN pump. I'll service the old one and keep as a spare.
Art Pearse

That way, the new one will never fail. RAY
rjm RAY

Art - You would be better served to service the points in your existing pump and keep the all electronic pump as your back up. The points depend on the small amount of arching at the points to keep the contacts from filming over. I can just about guaranty that if the points style pump sits for several years until the all electronic pump acts up, the points pump will not start up at all and you will have to service them at that point (when it may not be convenient to do athe time. Cheers - Dave
DW DuBois

If in doubt put two pumps in series with a change over switch, or even easily accessible wiring connections. That way you are carrying a spare already plumbed in. I have a points SU and a Facet.
Allan Reeling

"I can just about guaranty that if the points style pump sits for several years until the all electronic pump acts up, the points pump will not start up at all"

Indeed, new points pumps come with a slip of paper in the box saying to clean the points before returning it as faulty. In the past I have got one working on a garage find just by bridging the points with a screwdriver several times, which operated the solenoid and moved the points enough to get the pump working and the car going.
Paul Hunt

Just get a wasbro pump and all your troubles will go away.
R Cintas

FWIW, I've had the electronic style SU in my 79 for over ten years with no problems.


79 MGB
gary hansen

I have found both the electronic and points versions to be extremely reliable. In the midget, the pumps with points have each lasted 20 years. The latest is electronic and so far is fine.
Glenn Mallory

This thread was discussed between 19/04/2016 and 17/05/2016

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