[sgwilson904]

Before I get to Follow-up/Update #4, as promised, let me say how much I appreciate that Model A folks seems to have what my mother used to call "the patience of Job." I appreciate you all sticking with me here and continuing to come up with ideas as we struggle to solve this mystery. Your suggestions, coupled with the help from the guys here in the Jacksonville A's, is keeping me at it.

My pal Mike, an old Navy vet (in the military service, not the store at the mall) has two A's of his own and he's been helping me implement some of the suggestions posted here. I'm surprised he hasn't yet suggested we drive the thing off a pier and see if it floats but he helped me work on it again yesterday and there are some new developments to report.

A couple of days ago, I noticed a few drops of gasoline dripping onto the floorboard from the sediment bowl fitting against the firewall. In tightening that, we noticed there appeared to be no silicone tape or liquid sealer applied to the threads. On the ride home, I discovered our tightening had increased the problem and now there were several drops on the floor. I turned off the fuel valve, ran the engine until it stopped and let it sit overnight which temporarily suspended the link.

Yesterday, we removed the inside fuel lines and found some silicone on one end of the threads but not the other. When we also removed the sediment bowl fitting for closer inspection, we discovered someone had once cross-threaded the threads of the inside fuel line connection. We replaced the fitting with a new one, using the liquid sealer instead of silicone tape on both ends. That solved the leak...but on a test drive, Mike determined the carb was running a little rough and we ought to swap it out to see if THAT is part of our big problem.

Once we removed the carburetor, we noticed just inside the fuel line was some white, stringy junk we took to be silicone. It wasn't clear if this was from the threaded fitting on the carburetor itself or whether this had come from inside the fuel line farther upstream. We dug all of it out, opened the carb to assure there was not any more inside, then put it back together. This seems to be right in line with the suggestion of Old 182's experience posted above (#173).

Now, with a leakless fuel connection and all silicone tape removed from all fuel line fittings (replaced now with the liquid sealer) and string stuff all cleaned out of the carb, we're ready for another long test drive today.

Recent posts that suggest hot fuel lines causing vapor lock--see #164, 167 and 172 above--led me to another discovery I've never thought about.

My fuel line from the firewall to the carburetor does not seem be too close to the engine at any point. JBohannon (post 172) asked for an exact measurement. The closest point is 3 inches from the manifold. I've posted a picture below. But in examining this, I also notice that my fuel line appears to be BRASS and not the STEEL lines most cars use and is sold by the parts houses.

My Internet research shows brass to be a better conductor of heat than steel, perhaps as much as 10 times more conductive. Could this play a role as a contributory factor if not a causative one? This is another cheap fix I could try if you all think it's a likely problem.

Finally, speaking of fuel line, let me also respond to the clothespin idea from Boober49 (post #165 above). Back in the hottest days of the summer when everybody in the club was convinced this was vapor lock pure and simple, we put enough clothespins on that line to hang two week's worth of laundry! They were cheek-by-jowl along the entire length...but did nothing more than provide much comic relief from some of our veteran members who were sure I was an idiot. And of course by now, I've given them much more evidence to support THAT point of view, haven't I?

So, when it warms up here a little, I'm off down the road to St. Augustine again to see how it runs post-cleaning the silicone crap. I'm hoping Old 182 might be onto something. If not, I'll drive 40 miles to fill up on pure, no-ethanol gasoline and try that, too.