Sudden terrible gas mileage; or, The Disease with No Symptoms

The results are in.......bad Bosch AFM, as reported by the two top Fiat gurus in our local club, who took in the car this past weekend. I suspect their replacement of the AFM will also cure the poor gas mileage issue that started this whole thread. Thanks to Carl for his personal help, and his suggestion to bring the car to real mechanics :)
 
DSpieg said:
Had just enough free time this weekend to check the cam timing (it was spot on) and pull the spark plugs (see photo, a bit oily but they look normal to me). The only thing that didn't seem right was how easy it was to turn the engine via the crankshaft pulley with the spark plugs still installed. I didn't feel much if any compression. So what's the next step, compression test?
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These plugs are FAAAAAR from "normal." The dark black soot indicates a crazy-rich condition.
 
The car reeked of fuel rich exhaust when I went over to look at it. I'm not an FI and could only make the one suggestion that lead to his car being fixed.

Dave, sounds to me like you don't consider me a "real" mechanic.
 
Carl, you're an awesome Carb mechanic, but you told me yourself you weren't an FI guy - that's all I meant by that. Nor do you take on work for money, as far as I know. For that reason I can't call myself a "professional" musician, because the vast majority of my playing nowadays is voluntary, not paid.
 
I guess I can't tell the difference between oil-sooty plugs (with which I was very familiar on my now-deceased Alfa 164) and over-rich mixture-sooty plugs. What IS the difference in appearance, for my edification?
 
Car has returned home, drives perfectly, not enough miles yet to report gas mileage, but the exhaust smells like fresh-cut roses* instead of raw gasoline.

*OK, I'm exaggerating a bit
 
Thanks Carl, thought I had done that, but apparently not! My personal problem is clearly memory loss. My X1/9's problem was a bad Bosch airflow meter (AFM). According to Erskine there were three electrical values out of spec, but I don't have more details.

This is the 7th car I've owned over the last 40 years that had Bosch L-Jetronic injection (three X1/9s, three Alfa Milanos, and a VW Vanagon), and this is the first AFM that's failed. So I'm surprised. I'll report back after I've driven through a tank of gas and know what mileage the car is getting.
 
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