HELP! secondary/fuel problem - ZR-1 Net Registry Forums

george henry · 08-29-2006

Hi. New to the forum, so be gentle. I've been reading up on secondary system problems. Full power works fine until the engine gets really hot. Then it starts to fall on its face. Fuel pressure testing shows pressure jump to 52psi, then when the pump shuts off it drops quickly to 42 psi and holds. This is true with the primary pump alone, the secondary pump alone, or both pumps. Engine idle pressue is at 42 psi with the gauge jumping around that number. With engine cold I put a vacuum pump on the line going under the plenum; gauge would very slowly bleed down from 12"hg. With engine hot, no blead down. Car vacuum pump works fine. I have reinforced the air duct so I don't think that is the problem.
HELP WOULD BE VERY APPRECIATED

08-29-2006	#1
george henry Join Date: Aug 2006 Location: San Diego, CA Posts: 24	HELP! secondary/fuel problem Hi. New to the forum, so be gentle. I've been reading up on secondary system problems. Full power works fine until the engine gets really hot. Then it starts to fall on its face. Fuel pressure testing shows pressure jump to 52psi, then when the pump shuts off it drops quickly to 42 psi and holds. This is true with the primary pump alone, the secondary pump alone, or both pumps. Engine idle pressue is at 42 psi with the gauge jumping around that number. With engine cold I put a vacuum pump on the line going under the plenum; gauge would very slowly bleed down from 12"hg. With engine hot, no blead down. Car vacuum pump works fine. I have reinforced the air duct so I don't think that is the problem. HELP WOULD BE VERY APPRECIATED