About 25 years ago I had a very similar problem with my Sprite. It was
ultimately the fuel pump.
How did I prove it was the pump without rushing out and buying a new one?
Because back then I had a lot more time than cash - so I got a piece of
exhaust pipe about 5in long, welded in two pieces of fuel line in th side of
the pipe - one piece about 1in from each end of the pipe - and then welded a
welch plug into either end of the pipe to seal it - and a third piece of
fuel line into one end (right at the top).
Then - I welded on 2 brackets - so it mounted onto the inner ram tube bolt
off each SU, and changed the fuel line so that the fuel line went into my
new reservoir - and then gravity fed independently into each SU bowl.
It solved the problem - of course. It held enough fuel that the pump could
catch up - and fed the carbs by gravity.
It worked so well in preventing fuel surge and catering for a weak pump - I
made one for every SU carb card I ever owned since. Because sometimes - even
good pumps suck air on steep hills, under harsh cornering etc. And putting
it up higher than the float bowls moved it that much further away from the
exhaust heat...
:)
Its probably just the pump.
Chris
----- Original Message -----
From: "Simon Lachlan" <simon.lachlan@homecall.co.uk>
To: <pdeturck@rochester.rr.com>; <healeys@autox.team.net>
Sent: Tuesday, June 28, 2005 5:32 PM
Subject: RE: high rpm - misfire - followup
> Hi,
> Are you 100% sure that you don't have a fuel problem?....fixing everything
> else may have helped overall performance but not made the original issue
> go
> away?
> I guess you've got 2 carbs and wonder if the second one is getting enough
> gas when it all heats up down there. Maybe the pipe to the second carb is
> a
> bit grotty inside. Do you have those little mesh filters in the banjos?
> They
> get blocked up.
> Do you have an inline fuel filter in that area? I did and had all sorts of
> problems until I took it out. I never knew how it was causing trouble - on
> acceleration and load, particularly on steep hills - but it was and
> removing
> it made a huge difference.
> What is the heat shield like? I don't know much about BJ8 heat issues, but
> I
> know that they can be major other Mks.
> Simon.
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