Guest Anonymous Posted February 26, 2002 Share Posted February 26, 2002 Hi, I'm new to this board, and over the past few weeks I've been reading many interesting posts and replys. I purchased a hybrid Z car last summer. It's a '77 280z with a mid-70s Chevy 350, 3 speed automatic, mild cam, AFB 600 carb, and Holley electric fuel pump. My problem is that my car is very prone to stumbling and flooding. I installed a fuel regulator between the fuel pump and carb, but the adjustment on the regulator doesn't seem to affect the pressure. (I installed a fuel pressure gauge on the regulator) I'm reading over 12 pounds of fuel pressure, which I know is about 6 pounds too high. I think that the carb needs about 6 pounds of pressure, else the excessive pressure floods the fuel bowls. Does the regulator need a fuel return back to the gas tank to work properly? If so, I don't see a connection on the regulator to make it work. I notice that when I screw the gas cap on all the way, the pressure in the gas tank really builds up. Upon loosening the cap, the pressure comes out with a whoosh! When I keep the cap loose, the stumbling and flooding problems are less severe. Should I drill a small hole in the fuel cap to permanently keep the fuel tank de-pressurized? After all, this high pressure is not needed since I don't have fuel injection. Sorry for the long post, but I wanted to see if anyone else has had the same problem, and if so, how they cured it. Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted February 27, 2002 Share Posted February 27, 2002 Rick-man: -are you positive your pressure guage is on the correct side of your regulator? If so and your regulator isn't altering fuel pressure then it's not working and you require a different one (assuming your regulator is for correct pressure range & guage is working). -is your fuel tank 'pressure' positive (expansive) for certain? or possibly a vaccuum? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted February 27, 2002 Share Posted February 27, 2002 Ross, Thanks for your reply. Regarding your answer, I'm not sure what you mean by "correct" side of the regulator. The one I bought has one inlet and two outlets, presumably for a setup with two carbs. Instead of blocking the other side, I installed a pressure gauge there. I haven't tried switching the outlet line (to the carb) with the fuel gauge. And, yes, I'm sure that the gas tank is pressure positive. When you loosen the tightened cap, the air comes out in a whoosh, not sucking in, like a vacuum would. Rick Quote Link to comment Share on other sites More sharing options...
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