Interesting Henry!
We had fuel handling problems at Blackhawk and again at Mosport. Then the
Holley quit delivering altogether at Moss Corner. (Great place to watch
everyone
else have fun)
With help from Uncle Jack and Kas I put another pump in and fuel handling was
totally cured.
Back in Iowa I dismantled pump and inspected. No significant debris. Put it
back together and it worked again. It must have been the pump vane hanging up
as you indicate.
Holley is about 7 years old and pump vane replacement kit may be answer, but
not sure I want to take the chance. I will it use it as a back up pump.
Thank you for your insight.
>
> I have been fighting fuel problems ever since I changed out a little Facet
> cube pump and an el-cheapo fuel pressure regulator for a Holley Blue Top
> pump and a Holley regulator. My fuel pressure gauge would show an
> intermittent fluttering accompanied by a distinct buzzing coming from the
> regulator. I swapped the regulator, I tried both the 1 to 4 PSI and the 4.5
> to 9 PSI regulator that comes packaged with the fuel pump. Both did this
> from time to time with the engine running or not. At Mosport I had things
> running pretty well (with notable exceptions!) but running the Triumph
> feature I found some times the car would take full throttle happily, and
> some times it seemed to bog down at anything more than 4/5th throttle.
>
> So I decided to replace the fuel delivery system from the pump to the
> carbs. I ran new 3/8th's inch hard line from the pump to the new regulator.
> While I had the pump in hand, I decided to drop the bottom off and take a
> look.
>
> The pump is of the basic rotor and vane variety, the rotor sits off-center
> in the round pump bore, and 4 little vanes slide in slots in the rotor. As
> the rotor turns each vane slides in and out of it's slot, remaining in
> constant contact with the bore. Centrifugal force at play here.
>
> I found the pump cavity as clean as I could have hoped for, the debris
> screen was perfectly clean. I spun the rotor by hand, and I found my
> smoking gun. One of the vanes was stuck in it's slot. It easily became
> unstuck with a tiny amount of encouragement, but no doubt the vane was not
> doing what it was supposed to. Holley sells a rotor and vane replacement
> kit, which I installed, but I have lost all confidence in the design of the
> pump. I see no reason for this failure to have happened. The rotor and
> vanes I removed from the pump look fine, and the vanes slide freely in the
> slots. Perhaps something in the race fuel???
>
> Any recommendations on fuel pumps OTHER than Holley?
|