New Fuel Line
So as I had noted in my last post, I felt that the main section of fuel line had to be replaced. I ordered a twenty-foot coil of 3/8″ copper-nickel fuel line and used my brake flare kit to set up a double-flare on each end. This line replaced what had previously been three sections of different types of tubing extending from the gas tank to the engine bay, each joined by rubber tubing and hose clamps.
The new line replaces all of that – the only line left in place was a nicely bent section extending from the driver’s side of the engine bay to the passenger side, where it connected to the fuel pump. From the fuel pump there is one more section of line extending to the fuel filter, which is then directly connected to the carburetor. I used an air compressor to blow out the lines I retained after they were drained of fuel.
I’d like to note that to straighten the coiled line, I had at first looked for a tubing straightener like the one pictured above. Then I found out they cost around $200! So I did a little more research and found where a fellow had simply pulled his tubing through some piping to straighten it. So I purchased a 1/2-inch diameter, five-foot long section of PVC pipe for $2. I pulled the tubing through it and was VERY impressed with the results. It came out with a slight curve, and then I rolled it on the floor to get the section (fourteen feet) as straight as an arrow.
After installing the new line, it only took a short while before the truck fired right up. With the proper fuel flow, I was then able to set the idle mixture and speed. It idles smoothly at between 850 and 900 rpm now.
The only problem now is the inability to get the truck out of the garage due to several weekends in a row of cold, rainy weather! I need to test drive the truck under load to know for certain that the line replacement finally addresses the stumbling issue.