I learned something I wanted to share with all listers.
I installed a Webber Carb kit from Victoria British a couple of years ago.
I had been using an OEM SU fuel pump for some time but at some point in time
I replaced it with a universal fuel pump from Advanced Auto. Things just
never seemed quite right and I adjusted timing, put on a pertronix point
system, and adjusted all I knew to adjust. I could never get rid of the
backfiring at low RPM only when the engine was cold???
After reading a bit on the Weber Carbs and looking at some other posting on
the internet I learned that Weber Carbs are very particular about fuel
pressure. They prefer 2.5 to 3.0 lbs of pressure. My universal fuel pump
was probably putting out 14 lbs. I installed a Holley 12804 low pressure
fuel regulator from Advanced Auto.
It is like UNBELIEVABLE how much it helped. Backfiring is gone and
acceleration and performance has improved tremendously.
The fuel regulator is rated at 1-4 lbs. I did not take the time to rig up a
fuel pressure gauge but I know I am at least close now (could be one lbs
over). I don't know what an OEM SU fuel pump puts out but it must be closer
to what the Weber likes because my problems were not as bad previous to the
universal fuel pump but never real good.
My suggestion is.if you're using a Weber Carb.KNOW YOUR FUEL PRESSURE. Has
anyone else run across this problem before??
Mike Lewellen
Lewellen@usa.net
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