Re: Proper fuel pressure for BBC\Holley 770
It can be the fuel pressure being too high but it can also be the idle vacuum being too low due to perf cam,your sligthly retarded inital timing with the cam your running thus causing the power valve to open prematuly causing a very rich idle and low spped fuel mixture which is a very common thing to happen with a perf cam or it could simply be a bad/blown power valve.
That cam needs approx 18 deg btdc initital timing for best perf & idle vacuum so crank in a couple more deg initial with idle low like 550-600 rpms to keep mech adv from activating along with the vac adv unhooked/plugged when adj the initial timing.
Also,check the idle vacuum after you crank in the 2 deg additional initial timing to see what it is,it should be approx 13-14 inches + - with your cam.
Then check to ensure you have a 6.0-6.5 power valve if the idle vac is somewhere around what i est with the 18 deg initital timing and not the slightly retartded 16 deg initial your running that can cause sa lightly lower idle vac reading.
1969 CHEVELLE SS396,ORIGINAL #'S MATCH,GOT IN 1978,(In 2001 rblt/bored original 396 .030 to 402)/M20/12BOLT/3:31'S
2002 MAXIMA (DAILY DRIVER/1 owner,GOT 3/2013 w-44k miles)
2009 HD ELECTRAGLIDE CLASSIC ULTRA (GOT 11/14 W-9,700 miles)
Last edited by SWHEATON; Dec 12th, 06 at 11:26 PM.