rexus31
Senior Member
I thought I would post this in the hopes of helping someone out down the road.
Ever since my famous Fusible Link issue, my car was still running like crap; running rich and stalling. I rebuilt the carb; replaced the distributor, cap, rotor, ballast resistor, ignition switch, fuel pump, fuel filter and troubleshot the fuel tank and sending unit. Nothing changed the problem. It was running rich and I had no response from the idle mixture screws. The car hasn't been on the road in months. Steve (saforwardlook) took my carb and ran it on one of his '65 300L's and reported it ran flawlessly with no issues concerning adjustment or running rich. Alas, something eliminated. He brought the carb back to me today and planned on a couple hours of troubleshooting. We started with the PCV. I cut my thumb trying to remove the hose from the PCV valve and had to head in to get a Band Aid. When I came back, Steve had reported the PCV was very loose, just dangling in the cap. He tightened it and the car now runs perfect. We had both never thought to check the PCV until today. Normally, a vacuum leak would cause a lean condition. Steve cited a MAJOR vacuum leak at the PCV caused the metering rods in the carb to stay open, thus causing the over rich condition. The vacuum leak was also the culprit in the operation of the idle mixture screws, essentially rendering them useless. Lesson learned: check the simple things first.
Thanks again Steve for your help!
Ever since my famous Fusible Link issue, my car was still running like crap; running rich and stalling. I rebuilt the carb; replaced the distributor, cap, rotor, ballast resistor, ignition switch, fuel pump, fuel filter and troubleshot the fuel tank and sending unit. Nothing changed the problem. It was running rich and I had no response from the idle mixture screws. The car hasn't been on the road in months. Steve (saforwardlook) took my carb and ran it on one of his '65 300L's and reported it ran flawlessly with no issues concerning adjustment or running rich. Alas, something eliminated. He brought the carb back to me today and planned on a couple hours of troubleshooting. We started with the PCV. I cut my thumb trying to remove the hose from the PCV valve and had to head in to get a Band Aid. When I came back, Steve had reported the PCV was very loose, just dangling in the cap. He tightened it and the car now runs perfect. We had both never thought to check the PCV until today. Normally, a vacuum leak would cause a lean condition. Steve cited a MAJOR vacuum leak at the PCV caused the metering rods in the carb to stay open, thus causing the over rich condition. The vacuum leak was also the culprit in the operation of the idle mixture screws, essentially rendering them useless. Lesson learned: check the simple things first.
Thanks again Steve for your help!
