I don't know about the 911 or the white bottle stuff, but the grey bottle I use makes the exhaust smell different, so I'm guessing your right abou that.
It somewhat makes sense that the front tank could be gelled.
Less volume and more contact area to the container to the outside temp. May have been at that criticle point where that tank just didn't take as long to gell. Give it enough time and possible the other tank may have done the same thing.
fuel line gel-in is one place...but TYPICALLY its the water in the fuel that
creates the biggest problem. (and your more likely to have water IN
the tank then in the fuel lines...assuming the filter is working properly).
freezing at the filter/separator happens..and is another likely source
for blockage...its also why some (ford included) filter/separators are heated.
#2d SHOULD be have GOOD flow property to about 6*f
#1d is generally forumulated to flow as low as -40*f
I guess you are correct on that part of the gelling in the lines. But the fuel in the filter housing may be fine from the ambient heat from running the engine in the morning as it sits right on top.
But as for the fuel lines yeah you got me there....must have been good enough to flow and then when you switched over to the fuller tank it was good to go.
But here is a question. With all of that fuel in the fuel filter housing I assume you could run a good 15-30 seconds on the highway by the time you actually start to pull air at a tank or meet blockage. It seems there is a good 1/3 qt in that fuel filter housing. Not like that would ever do you any good but just wondering if it worked that way.
thank god when it died i wasn't on the highway, i actually was about to leave the parking lot of work. the first thing i did was open the filter housing and check the fuel. it was only about a 1/4 or 1/3 full, the fuel was clean and looked clean, the filter was clean as well. must have been gelled in the tank and had enough restriction to starve the engine.
If it gelled at the pickup screen in the tank (or any restriction) the vac on the line will open a valve thats a few inches above the screen to allow fuel flow. Now with a 1/4 tank of fuel you will pull air into the system. I would say you pulled air into the fuel system and the injector knock you here is due to the high oil pressure compressing the low volume/pressure fuel in the injector.
Your problem was a combo of both (gelled/air).
Not only the use of anti gell is important in cold weather. Keeping more than 1/4 tank of fuel in tank is also recomended due to this issue.