Fuel in Air Cleaner

[79Temecula]

Hi all,

I have a 1979 Spider 2000 with a stock air cleaner, 34 ADF carb, and the dual plane intake. Since I bought the car, I have had issues where fuel is getting into the air cleaner and saturating the filter. I finally rebuilt the carb completely but continue to have the same problem. The top gasket makes it seem like the fuel is saturating near the venturi the most--especially near the choke.

Everything I've found here has pointed to the float level and needle. But I've checked the float multiple times to make sure the measurements are accurate as well as the float needle and seat for any dirt. Anything else I should look at or try?

[18Fiatsandcounting]

The '79 carbureted engine had a lot of vacuum plumbing and other emissions stuff going on. Any chance the fuel is coming from some part of that, and not the carb itself?

Another possibility is that you have excessive blowby coming out of the crankcase breather tube, but that tends to be more oily and slimy than straight fuel.

-Bryan

[79Temecula]

I don't think it's excessive blowby because the breather hose is pretty dry. I assume it would be coated in a layer of oil, right?

[18Fiatsandcounting]

If your breather hose is dry, that's a good thing, and so it's probably something else causing the fuel buildup in the air cleaner.

About the only way you can get fuel back up through the carburetor into the air cleaner housing, is to have some serious issues with backfiring through the carb, or fuel shooting back up the venturis if the engine is seriously mis-timed. But, if it were, you would hear the backfiring or popping. Since you don't hear that (right???), then we're back to an emissions connection somewhere that is leaking fuel into the air cleaner housing.

-Bryan

[79Temecula]

I recently had to rebuild the distributor and reset the timing, so it could be that. I can't imagine what else it would be. I was reading about bad valves not closing, but I haven't heard any obvious backfiring or spitting. The carb size or jets wouldn't produce issues would they? I'm worried the 34ADF on the dreaded dual plane intake may be a problem (too much fuel going into a very constricted space).