Reply to "Cat acts like runnig out fuel"

PRESUMING that the car was running fine and this is a recent occurrence, you need to check both the idle air bleeds, the idle fuel transfer slots and the main air bleeds.

In order to do this you will need a numbered set of drill bits and a pin vise. Holleys are particularly susceptible to any of these clogging with foreign matter.

It is a 50/50 situation of which it is. IF you had ANY kind of a backfire then it is probably the idle transfer slots located in the throttle body near the the throttle plate intersection at the idle or near idle position. That is where the engine is feed atomized fuel from at least up into the 2,000 rpm range.

I don't have a diagram to show you a picture but you can probably access one on the internet of the Holley instruction sheet on what these things look like and where they are located.

You are going to need to remove the carb, drain it of fuel, turn it upside down and remove the bottom throttle plate on the carb to service it. It isn't difficult and you do not need to be even a German Rocket Scientist to do it.

It is also possible that you have foreign debris in the idle air metering bleeds (air metering jets) located in the top of the main body on the primary side. That could also be from a backfire since it is under the choke plate OR could have happened if you had the engine running with the air cleaner off.

You want to match up the drill bit size as closely as possible to the existing orifices without enlarging them.

The well on the idle air bleeds is fairly deep and you need to run the bit completely into it to make sure something that was liquid -ish didn't drip down into the well and solidify in there. It isn't very likely but you just won't know exactly what happened here. Like I said, it's a 50/50 proposition whether it is the air bleed or the fuel transfer slot. Sometimes it is both.

A backfire tends to create an oily black carbon that the engine has liquefied in an instant then it cools almost as fast into a Crazy glue type of material and plugs one of the orifices.

This is very common on Holleys, particularly the smaller capacity ones like an 1850 that has smaller orafices for smaller and more economical running. I've clogged up a few myself and can tell you that using a cab spray cleaner and compressed air alone will not get the job done. You have to physically remove the obstruction with the drill bit. Then you can use compressed air to blow it away.

Soaking the carb generally won't do it either. Don't even bother with that.