[Healeys] S U fuel pump

Kees Oudesluijs coudesluijs at chello.nl
Tue Oct 20 00:31:34 MDT 2020

When rebuilding SU electrical fuel pumps I ad a transil (e.g.. 1.5 
KE18CA) over the points, parallel or in stead of the capacitor if 
fitted. This reduces the max voltage across the points to 18V instead of 
several hundreds when the contact is broken and the points spark.

It is also important to clean and polish the points using flower paper 
(2-3000 grid), also when new!!

A transil is more or less a bi-directional Zener diode. They cost next 
to nothing. I buy them in bulk and pay about $0,15 but when buying only 
one expect  to pay between $1 and $5. Ebay is an excellent way to source 
transils (mainly from China).

A transistor circuit similar to those used in early transistorised 
ignition systems does a similar job by limiting the current through the 

Kees Oudesluijs

Op 20-10-2020 om 07:50 schreef Ray Juncal via Healeys:
> I'm rebuilding a couple of early S. U. fuel pumps for my 100. In 
> checking my reference files I came across an article from the MG club 
> about adding a transistor circuit to reduce the amps across the 
> points. That would keep the points from burning and extend the life of 
> the points. Has anyone on the list tried this? The author of the 
> article claims he has 20,000 miles on the conversion and new looking 
> contact points. Thoughts, comments, suggestions.....
> Regards
> Ray
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