I installed a suppose to be new Holley 600 carb on my 302, but it started running rough and not idling. When I shut it off, I looked in the carb and noticed the back 2 barrels were dripping fuel into the intake which would cause it to flood out. I don't think anything else would cause it to do this except the carb. I'm going to re-install the motorcraft 2 bbl and see if that cures it. It sounds as if the Holley may have some trash in it but everything is new including the tank, fuel pump, carb and intake as well as the fuel lines. There should be no trash in the system.
Should be, and what happens in real world are often different things... Most Holleys have a sight plug in the passenger side of the bowls that fuel level can be checked... It's fairly easy to pull a bowl(especially rear), and check for dirt in the needle valve...
If the float level is set to high. This will happen. Even on a new carb it will need minor adjustments.
Don't put the 2-barrel back on. Adjust your floats, make sure the needle & seat is clean, and make sure the secondary throttle blades are closed at idle.
I think I found the culprit. Trash in the carb. I replaced everything fuel related prior to the new carb EXCEPT the metal fuel line from tank to fuel pump. Must have a lot of trash in the old lines. Will need to replace or blow/clean them out.
Even w/ trash in the old lines the fuel filter should have kept the trash from entering the carb. You do have one (fuel filter) , right?
The only filter the car had at the time of the new carb install was one on the line right by the tank. There was not one between the pump and the carb. There is now.
Glad you got it all sorted out. I'd recommend another inline filter right before the carb. Only takes one little spec in between the needle and the seat.
Do you still have the sintered bronze filter in the float bowls? If you did, that trash would not be there. In your application, that bronze filter will make NO difference in performance contrary to popular belief.
Had same problem with my 1984 302 ho motor.New fuel tank and filter in line at carb.Needle and seat gushing out vent tubes and more then once replaced.I used summit copy of ford carb run perfect high cam and electric choke.
you can beat the price of the Summit brand of the Holley Carb wet flow tested bolt on and go all the features of the Holley carb half the price and they run great
