'51 Special
Active Member
The backstory is that, after I bought my '51 special at auction in 1992, I soon discovered that it would regularly starve for fuel, acting like it was out of gas no matter how full the tank. I tried lots of things: rebuilt the carb and fuel pump, had the gas tank steamed out, then etched and sealed with Bill Hirsch's products. Nothing seemed to cure the problem. I ended up puting a 2.5 gal. tank in the engine compartment, gravity feed direct to the carb. Not a practical solution except for yard driving, so she mostly sat for almost 20 years. Fast forward to last fall. I was going to do a general teardown, and hooked up a marine tank to the flexible end of the gas line about 24 inches back of the fuel pump. The fuel pump and carb worked like a charm, at least for the ten minutes or so I ran it.
During teardown, I pulled the tank, found it still was holding a gallon or so of 20-year old gas. I blew out the main fuel line and pulled the gas tank sender unit to verify the float hadn't fallen off (it has a cork float held on with copper wire that is soldered to the original float arm, a fix necessary as the original float was holed), and discovered that the fuel line running through the sender unit was completely blocked. Thinking aha, I have cured the original problem, I cleaned the line out by chucking into a drill a couple of strands of wire from a small diameter steel cable. Installed everything, put five gallons of gas in the tank, and tried to get it to fuel the engine. No go. I disconnected the fuel line where it exits the frame to the flex line by the engine, and blew a little air into the tank. Well, it ran gas out of the line just fine. Matter of fact, it siphoned gas out of the tank, and ran about a gallon into the drain pan before I could get the gas line reconnected. While preparing to pour the gas from the drain pan back into the tank, I noticed a few crumbles of rust, so I used a funnel with a screen, thinking: "I hope that rust was in the pa before the gas was.
So, I start the car with primer, and soon it is running on its own. I run it about 10 minutes, shut it off, do other stuff for an hour, and it starts right up again. I drive it about 20 feet, and it starts starving for fuel... just like 1992.
What the hell?? I thought, I'll take off the fuel pump bowl and find it full of rust crumbles, just like I found in my drain pan. So I took off the fuel pump bowl and found not a speck of rust. And, it was full of gas.
I know I could by a new gas tank and sender. (Just $325 plus shipping and I'm made out of money.) But what good would that do? The tank doesn't leak, the sender and all other gas lines flow fuel. The fuel pump gushes gas (at least when I'm looking), the engine runs like a watch when it isn't starved for gas.
I'm about out of ideas, except for maybe again rebuilding the fuel pump.
Has anyone ever had this problem? Did I maybe mis-assemble something 20 years ago when I last rebuilt the fuel pump? But is it even possible to put it back togather wrong and have it still work part of the time? Or does anyone have any suggestions for what to try next?
'51 Special
During teardown, I pulled the tank, found it still was holding a gallon or so of 20-year old gas. I blew out the main fuel line and pulled the gas tank sender unit to verify the float hadn't fallen off (it has a cork float held on with copper wire that is soldered to the original float arm, a fix necessary as the original float was holed), and discovered that the fuel line running through the sender unit was completely blocked. Thinking aha, I have cured the original problem, I cleaned the line out by chucking into a drill a couple of strands of wire from a small diameter steel cable. Installed everything, put five gallons of gas in the tank, and tried to get it to fuel the engine. No go. I disconnected the fuel line where it exits the frame to the flex line by the engine, and blew a little air into the tank. Well, it ran gas out of the line just fine. Matter of fact, it siphoned gas out of the tank, and ran about a gallon into the drain pan before I could get the gas line reconnected. While preparing to pour the gas from the drain pan back into the tank, I noticed a few crumbles of rust, so I used a funnel with a screen, thinking: "I hope that rust was in the pa before the gas was.
So, I start the car with primer, and soon it is running on its own. I run it about 10 minutes, shut it off, do other stuff for an hour, and it starts right up again. I drive it about 20 feet, and it starts starving for fuel... just like 1992.
What the hell?? I thought, I'll take off the fuel pump bowl and find it full of rust crumbles, just like I found in my drain pan. So I took off the fuel pump bowl and found not a speck of rust. And, it was full of gas.
I know I could by a new gas tank and sender. (Just $325 plus shipping and I'm made out of money.) But what good would that do? The tank doesn't leak, the sender and all other gas lines flow fuel. The fuel pump gushes gas (at least when I'm looking), the engine runs like a watch when it isn't starved for gas.
I'm about out of ideas, except for maybe again rebuilding the fuel pump.
Has anyone ever had this problem? Did I maybe mis-assemble something 20 years ago when I last rebuilt the fuel pump? But is it even possible to put it back togather wrong and have it still work part of the time? Or does anyone have any suggestions for what to try next?
'51 Special