On Sun, 13 Jul 1997 07:01:22 EDT mgbob@juno.com (ROBERT G. HOWARD)
writes:
>Hi Ron,
> The fuel pump on the early TFs was on the firewall, as it was on
>TDs. Apparently there was a vapor lock problem with it, as the pump
>was moved to a location near the fuel tank so it would pressurize more
>of this fuel line/system.
snip
There was an article about this issue in one of the British enthusiasts
mags recently. Although the article wasn't that good, it did seem to
imply that most if not all "vapor lock" problems were due to failure of
the SU fuel pump. The theory was that heat affected the fuel pump, and
when it cooled it would work again, which mimics the effects of vapor
lock. The writer felt that he had confirmed this by determining that his
car stopped because the fuel pump was not working. Again, the article
was not very scientific, but may help to confirm why the pump was moved
from the firewall to near the tank in later MG's. Besides better
pressurization, it may also have helped to get it out of the heat of the
engine compartment and into the stream of cooler air under the car. I've
decided that I will use a "backup" electronic fuel pump plumbed into the
fuel line near the gas tank and out of sight on my TD restoration. I'll
keep the SU for looks, but my experience with point-driven fuel pumps has
led me to distrust all of them, no matter the manufacturer.
David Littlefield
Houston, TX
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