so i ahve been having problems with my car since i added my holley carb. i also got a new pump at the same time and totally forgot about it. added a fuel pressure gauge today and the fuel pressure is at 3 psi! it is supposed to be at about 8. what would cause this preoblem??
You need 4-5 psi for most holleys and edelbrock carbs. What brand/model is the pump? Many are adjustable to get the correct psi for your carb.
Is it this one? This is the 110 gph pump, and it should be pushing 6 psi. If not, no adjustments that I know of. Might have a torn diaphragm. Of course, it could also be an obstruction or clogged fuel filter somewhere up stream...
unless you have a restriction in your fuel system the pump is not doing its job. you could have a clogged up sock in the tank, a collapsed rubber hose, a crushed steel line, something plugging up a fuel line, a plugged up fuel filter. i would get a gas can full of fuel and put a hose from the pump inlet to the gas can and start it to see if it will make the proper fuel pressure. if it does then you need to look for the restriction, if no then you need a new pump or see if you can rebuild the edelbrock pump.
Another thing to keep in mind, cheap fuel pressure gauges are not always accurate. I have a high-dollar gauge right after my regulator, and another cheapie one just before the carb, and they are always a psi or 2 different. If I recall correctly, my cheapie one reads 4-5 and my high-dollar one reads 6.
You didn't say what the problem you're having is. Pressure isn't as important as flow. You can have 3 psi pressure and still have the flow to supply the carb. The reason you don't use a high pressure pump with a carb is the only thing that keeps the flow into the fuel bowl in check is the needle/seat which is operated by the fuel float. Too much pressure will sink the float and flood the carb's bowl. The pressure is there only to push fuel into the bowl as the float opens the needle/seat valve. It takes very little pressure to accomplish this.