Let me offer two words (OK, points) of caution on these Hall-effect pumps:
1. The Hall-effect transistor has no track-record in this application.
2. If the Hall-effect transistor fails you are stuffed. No tapping the
pump body with a long-handled screwdriver as you drive along, no cleaning
the points at the roadside, no swapping the Hall-effect transistor for
standard points. Although presumably if you bought the Hall-effect unit for
your existing, points-style, pump, you would be able to swap that back..
I bought my V8 nearly five years ago with a Hall-effect pump. It's not a
home-made mod - it's too good - it looks like a factory job. It started
playing up a few weeks ago - audibly weak pumping and fuel starvation. I
managed to complete my journey and spent some time checking over the pump.
I am fortunate in that the electrics end of the pump is in the spare-wheel
space so could observe its action while pumping into a bottle. I could see
no obvious mechanical problems but every third or fourth pump it would
either skip one or start fluttering rather than give a full-stroke pump.
After several minutes of this it suddenly started working properly again,
and has since, but needless to say my confidence in it is now weakened - so
much so that I now carry a reconditioned points-type pump in the car.
Regarding the fluttering, it is interesting to note that the original points
design on the MGB also suffered from fluttering, and the later design
incorporates more hysteresis (i.e. the diaphragm has to move further in each
direction before the points switch over). I wonder how much hysteresis a
Hall-effect transistor has?
Personally, I would far rather have a transistor-assisted system, i.e. where
the original points switch a transistor, but can easily be switch back to
operating the pump directly if the transistor should fail.
PaulH.
MG Cars Webring MG Site of the Month - September '99
http://freespace.virgin.net/paul.hunt1/
(or if that URL doesn't work try )
(http://194.168.54.52/paul.hunt1)
-----Original Message-----
From: jonmac <jonmac@ndirect.co.uk>
To: Triumphs List <triumphs@autox.team.net>; MG List <mgs@autox.team.net>;
Britcar List <british-cars@autox.team.net>
Date: 23 September 1999 17:51
Subject: SU Fuel pump thread
>Friends
>
>I haven't been paying all that much attention to this thread
>but it seems to be rumbling on - and on. Below is an extract
>from the October issue of Triumph SIXappeal which you may
>find useful - even marginally interesting? No financial
>involvement of course and I don't have a web URL or e-mail
>address.
>
>John Macartney
>
>Editor - SIXappeal
>The Triumph 2000 2500 2.5 Register
>
>
>BURLEN FUEL SYSTEMS
>launch electronic SU fuel pump
>Burlen Fuel Systems of Salisbury has introduced a complete
>range of pointless SU solid-state electronic fuel pumps.
>While such items were not fitted to any of our cars as
>original equipment, some may have 'grown' them over the
>years. Equally, members may have other classics which do use
>SU pumps and for them, this snippet may be of particular
>interest.
>While the internals and method of operation of the Burlen
>pump is different to the genuine SU, the Burlen units are
>externally identical to the SU and they 'tick' just the
>same as well.
>Burlen have also introduced an electronic conversion kit
>whereby you can modify your current SU pump to electronic
>actuation.
>For further advice or technical info, contact Miles Harvell
>at Burlen Fuel Systems on +(44) 1722 412500
>
>UK callers to the above number obviously have to change the
>front end for national calls.
>
>
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