ECO VALVE

[Laredo81]

Hi everybody!

I have a 81' AMC Laredo with 360 in Hungary. I want to understand the function of the eco valve in the carburetor because this is not clear yet. When does it work? What is the reason it is in the carburetor? I'd like to know it because I took it to pieces to clean all the parts. (I have a Motocraft carburetor)

Thanx!

C.lard
AMC Cherokee Laredo

[Bob Barry]

The economizer valve, also known as the power valve, feeds extra fuel to the engine when it is under load, but cuts back the fuel fed to the engine when the engine is under no load.

Without the valve, the main jets in the carburetor would need to be much larger.

It is called an economizer valve because it allows the main jets to be sized much smaller, resulting in better fuel economy.

The power-valve in the Motorcraft 2150 2-bbl carburetor is a 2-stage valve, which feeds more fuel in two steps. It is triggered by engine vacuum.

It is also the same size as an ordinary Holley power-valve, so any performance parts shop that carries Holley parts should be able to get you a new valve, if one does not come with your rebuild kit.

[joe]

I'm not sure what the ECO valve in the carb is but I'm guessing it's what's known in the US as the "power valve or power enrichment valve." It sort of works like an accererator pump. It's to provide a bit more fuel during heavy loads on the motor or when runing at higher RPM's. If manifold vac isn't supplied to it or the diaphragm is torn/leaking the eng will idle really poorly and run poor. If you ever get a backfire through the carb on an MC carb...odds are the power valve just got blown out too.