Tach Pulse Signal (Carbureted)

On carbureted models, fuel pump cut-off relay control is dependent upon a tach signal being generated on the Blue wire of the ignition coil when ignitor triggers ignition coil. If this signal is lost, fuel cut-off relay will stop fuel pump. This signal may be verified at ECU Blue wire terminal A11. Using a voltmeter, lightly probe terminal and check for voltage with engine cranking. If voltage is not present, repair open or short to ground in Blue wire between ECU vand ignition coil.