I have a 66 Mustang coupe, 289, 2 barrel. It has been sitting for several years. I recently put in a new battery and was able to start the engine with the help of some of the spray fluid in the carburetor. It was running fine, but I noticed fluid draining to the floor. At first it looked like it was coming from the oil filter, but it was clear. Upon further diagnosis, it was actually gas coming from the accelerating pump assembly and draining over the oil filter.

When the accelerator pedal is depressed, gas comes out of a small hole in the bottom of the accelerating pump assembly. The picture in my manual shows this hole, so I am not sure what it is for and why gas is coming out of it. Obviously, I don't want to run the engine with actual gas leaking out of the carburetor.

Can someone advise the purpose of this hole and the proper function so gas does not come out of it?

thanks, Mike Cummins

 

No fuel should be comming out of there. Sounds like the diaphragm has a hole in it. Probably dried out from sitting.