So yours has the stock cam and exhaust manifold?
If so that's part of your deal. The webber puts a little more fuel in the engine. Without a cam or more air intake it will always be a little more rich than a stock carb.

You should be able to tell if it's rich by the smell of the exhaust.
Another thing is how your distributer advance is hooked up. If I'm not mistaken if you hook up the vac from the distributer to the intake port it will advance quicker and help burn the fuel. But it might be the other way around by hooking the distributer to the carb.

Anyway, check the timing, the o2 sensor and the egr valve cause they all effect the fuel consumption.
You might want to get a cold air intake too (or make your own) that will help quite a bit.

By the way I believe the carb adjustments only apply to idol. In other words the fuel screw does not effect the carb when you are revving or cruising. Don't quote me on that but research it. Good Luck

Quote from: wilderness on July 20, 2008, 03:22:35 PM

So yours has the stock cam and exhaust manifold?
If so that's part of your deal. The webber puts a little more fuel in the engine. Without a cam or more air intake it will always be a little more rich than a stock carb.

You should be able to tell if it's rich by the smell of the exhaust.
Another thing is how your distributer advance is hooked up. If I'm not mistaken if you hook up the vac from the distributer to the intake port it will advance quicker and help burn the fuel. But it might be the other way around by hooking the distributer to the carb.

Anyway, check the timing, the o2 sensor and the egr valve cause they all effect the fuel consumption.
You might want to get a cold air intake too (or make your own) that will help quite a bit.

By the way I believe the carb adjustments only apply to idol. In other words the fuel screw does not effect the carb when you are revving or cruising. Don't quote me on that but research it. Good Luck

  If he put a WEBER on it, the O2 sensor is doing nothing but blocking the exhaust.
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Your right, but how does the pcm deal with the signal that used to go to the old carb? Or is it just that, a voltage that needs no response?

And please forgive my extra B

I was talking about the computer, the computer sends a signal to the mixture control valve on the intake that is not on the carb it is on the intake. So even if you put a WEBER on it if that valve is still hooked up, the computer will still dictate the mixture going into the intake. That's what I was talking about.

Never the less, I was just mentioning simple things to look into to possibly help with his mileage. And you will notice that I suggested he research each of the things I suggested he should check.

I am not an expert by any stretch but I know from experience that it is better to make sure that all your ducks are in a row before you start adjusting the carb and in his case he stated it runs quite well.