472 Carb problem

[Lou clc 19028]

Hi all, I just installed a new fuel pump(nos delco)on my 70 caddy. I took it out for a test ride and it had a little hesitation on acceleration,but after it warmed up it was OK.Today when I started the car it idled high for a few seconds and then began to idle very low and rough.Upon pulling the air cleaner off you could see fuel puddling up on the carb and dripping all around. HMMM I restarted the car it still ran very rough.You could see the fuel leaking from the pump rod.It almost looks like it is flooding. When I raise the idle the leaking stops and the motor ran better. Did the new fuel pump blow the seals in my carb?    

[Lou clc19028]

Clarification: When I typed pump rod I was describing the one on the carb(not the fuel pump). Also the car ran fine until I touched it. Yeah.Yeah. I know,if it aint broke dont fix it.  

[Dale]

Hi Lou,
Im no expert, but it sounds to me as if the needle and seat that let the fuel into the carb is not working properly. The way its meant to work is when the floats reach the top of the float bowls, the needle closes in the seat and restricts further fuel flow and stops it from flooding. I am guessing that the new fuel pump has now exposed a worn needle and seat, allowing the float bowls to overfill and flood the carb. This would be why a fast idle cures the problem as the extra fuel leaking out is being burnt by the faster running motor. I suggest you try replacing them (very cheap), and see how you go. If that doesnt work, maybe your fuel pump was not the correct unit. If it is pumping too much pressure, this will also cause the carb to flood. Let me know how you go. Cheers,
Dale.

[Lou]

Well I took the top of the carb off cleaned everything up and blew some air thru it with my compressor. I put it back together and started the car.Presto! Good as new A piece of debris must have found a way into the carb and blocked the float up.  Thanks

[Dale]

Fantastic! Good for you.

[Michael Stamps 19507]

Did you check to make sure the filter on the carb was still in place?

Stampie

[Lou]

Yep I double checked . Carbs and me dont get along very well. I used my shop manual and my trusty Chiltons book the whole way

[Denise 20352]

  I would put a new filter in there, and make sure that the spring is in it, so that you can be sure that the kumquat seeds cant get in.

-denise

[bill henry]

the fuel filter is in the fuel pump on a 70 unscrew the big hex where the output line comes out