Stock fuel pump pressure

[prs143]

What should it be? I just put an underhood gauge on my original '81 pump and it reads 1psi at idle!! Is it on it's way out?

[doc221978]

Mechanical pumps produce more as RPM's raise. What is the pressure as it gets to 2-3,000 RPM's? Does the engine run lean?

If you are wanting to start raising you power levels I would replace it anyways to be on the safe side.

[74RAT]

stock mechanical pumps used with the quatrajet carbs put out somewhere between 7-9psig on average. the float leverage ratio is better on the q-jets for keeping the needle on the seat at the higher pressure than the holleys and eddy's.

you generally show the highest psig at idle when the fuel volume requirement is the lowest,, and should for sure have the float bowl full and needle and seat closed up,, for the most part.

i'd check the sock in the tank or the rubber line connections on the suction side of the pump. possible that it's sucking air in at one of the hoses/connections on the suction side??? if not,, then maybe a bad pump.

did the pump sit unused for a while,,, after having fuel in it previously? could be a dry rotted diaphram with no hole in it yet??
hope it helps,
andy

[1980RS]

Most stock mech. fuel pumps I ever had were around 5-7 psi except a carter that had 9psi. I would rather have a mech. pump on my bird right now after all the trouble I have had with electric pumps on that car in the last year.

Guess it's time to change to an older block.