[Healeys] Strange Problem

Alan Seigrist healey.nut at gmail.com
Sun May 11 19:41:14 MDT 2008


Nick -

Michael is pretty much a guru here, but his point 1. is off because the HD8
carbs on your BJ8 are fixed together with a fixed attachment so you can't
have one carb valve opening and the other stays closed with a Mk III - they
will both open and close at the same time, always.  Only earlier Healeys had
this problem.

I might suggest also, as an alternative, that it sounds like your car is
having a classic fuel starvation problem - when sitting at idle the fuel
pump pushes just enough gas in to keep the car idling and you can rev the
motor, but as soon as you start getting going your car needs more fuel and
loses all power because the pump can't keep up with demand.  Usually this
symptom will manifest itself if you've had some hesitation or loss of power
going up steep hills receently, than this is your problem.

Usually what causes this is:

1) a fuel line blockage (pull off the fuel feed pipe to the carbs and turn
on the iginition - you should have a very steady thoughput of fuel, if it's
just  a trickle, then this is your problem).
2) a clogged filter (if you have one inline, replace it.. also pop the tops
off the carb float chambers and check for gook and crud - if there is any -
clean everything including the float needles)
3) a bad fuel pump.  It is rarely diagnosed as such, but over time rust from
your fuel tank can aggregate in your fuel pump and reduce its performance.

Good Luck!

Alan


On Mon, May 12, 2008 at 7:57 AM, Michael Salter <
msalter at precisionsportscar.com> wrote:

> Hi Nick,
> I would bet that your impression that it is running on 3 cylinders is
> correct.
> I would suggest the following:
> 1. Have someone push down on the throttle while you check that the
> butterflies are actually opening, sometimes the clamps slip on the shafts.
> 2. Drive a short distance at full throttle then turn off the key, after
> stopping, remove the float chamber lids and check that there is fuel in
> each
> float chamber.
> 3. Remove the carb suction chambers and then, using a piece of tube, blow
> into the overflow tubes for each carb, fuel should squirt out of the jet.
> 4. while the suction chamber is off see if you can pull the metering needle
> out of the piston. Sometimes the locking screw comes loose.
>
> Michael Salter


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