After 6 months of intermittent success, a mysterious stalling on hard acceleration in my '69 350/300 has been solved. I now believe the reason the previous owner sold this low mileage highly orignial car at a bargain price price was this undisclosed stalling problem. Simply stated under hard acceleration the car would stall. This stalling was easily traced to being gas starved (float bowl empty). The car would always restart after waiting a few minutes. The records that came with the car showed that the pervious owner had it in the shop for several months during which time the carburetor was rebuilt, the fuel filters replaced, the fuel pump replaced, the gas tank replaced and all flexible fuel lines replaced. Upon discovering this problem I checked fuel pressure and flow at idle which were OK but just to make sure replaced again the fuel filters and the fuel sock in the tank with no results, then replaced the fuel pump which at first appeared to solve the problem however it reappeared after a few hunderd miles. At this point I instrumented the fuel line to the carb with a pressure guage that could be read while driving, and confirmed that on hard acceleration the fuel pressure dropped to near zero. At this point I confirmed the tank vent cap was correctly vented then ran a flex cable thru the fuel line from the pump to the tank and found no obstruction, next I removed the fuel pump again and checked that the pump push rod was not sticking and that the cam lift was correct. At that point I was totally baffled but decided to try one last thing and pulled the fuel pick up tube out of the tank to check for rust holes that might be above the fuel level in the tank. While I found the pick up tube in good shape I accidentally found that the fuel sock which I had previously replaced with a GM part from the local dealer and which looked perfect had a high flow resistance to fuel, when filled with fuel it took nearly a minute to flow thru. Removing the fuel sock solved the problem.
Since this stalling occured with both the fuel sock (unknown if original) that came with the car and a repalcement I installed, does anyone know if a fuel sock is supposed to be in place in this 69 model car???
Since this stalling occured with both the fuel sock (unknown if original) that came with the car and a repalcement I installed, does anyone know if a fuel sock is supposed to be in place in this 69 model car???
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