83-84z28

Hi I've got a replacement type fuel pump running off the cam and a SUmmit liquid filled fuel gauge mounted on a Spectre fuel rail going to my Edelbrock 1806 avs carb. How can I tell my true fuel pressure after warming up and sitting at idle the needle moves (bounces?) from 2.5 - 3.5 I guess the average would by 3 psi but I don't know. Also after running for a longer time the psi apparently goes down to 1.5 or so. Is my fuel pump going bad or am I reading the gauge wrong? If my pump is ging bad what would you suggest, Better quality mechanical or electric with a regulator?
Thanks

five7kid

iTrader: (14)

Sounds like the pump is getting weak. Replace it with either a good quality stock replacement, or the Carter M6626.

Auggie

Well, I don't know if this your problem but I had the same problem. I have a Stewert Warner elect fuel pressure gauge mounted in my car for my NOS system. I installed the sending unit just before the carb fuel inlet. I thought my fuel pump was going south so I did a pressure and capacity test (fuel pump tester) and everything checked out. So I removed the sending unit from the fuel line and noticed that the small hole in the unit was leaking gas. I shook the unit for quite awaile trying to remove the fuel. When I had all the fuel removed I reinstalled the unit, fired the engine and had 5# pressure. I think that the sending unit works on pressurized air rather then solid fuel. My sending unit is mounted on its side so I think that is the problem. It should be mounted upright to prevent fuel from entering the sending unit. Anyhow that is what worked for me.

Auggie

83-84z28

oh well cant expect to much from a 20 dollar pump. anyway do you think i will need a pressure regulator after the pump since i've read that the Edelbrock carbs seem to by picky about fuel pressure?

Auggie

Buy a fuel pump tester and and do the tests. It is real simple and you might learn something. Not a good idea to just throw parts at a problem. I have a stock L69 pump and it puts out 3 to 6# all the time. Paid $27 at NAPA.

Auggie

jstoltz

iTrader: (16)

I think I still have a return style carter pump around I was going to use it and decided to use my cv pump since it is rebuildable and use a return style regulator instead. I can check tomorrow if you are interested. If I still have it $20 and shipping it's yours

five7kid

iTrader: (14)

I wouldn't go that far. I've never had any problem with the Carter, or the stock AC replacement that preceeded it.

Shouldn't need a reg. I don't read everything available about Edelbrock carbs, but I've never seen that they're sensitive to fuel pressure.