MEFI Fuel Injection
Flooded Cylinders When you suspect an engine is hydrolocked, always assume the liquid is flammable. Disable the primary ignition system before removing the spark plugs. When cranking an engine without spark plugs installed, always disable the ignition system. Besides damaging the ignition system via ‘open’ secondary circuits, EFI systems use ignition reference signals to initiate fuel delivery!
Ignition Modules are sensitive to the amount of secondary voltage required to complete the spark plug circuits. With the spark plug wires removed from any available ground, the module will be driven at maximum dwell saturation time for the coil(s) – read as HEAT. And when that maximum secondary spark is released, it may seek a ground right back through the ignition module – causing instant electronic failure. When an engine is running with a spark plug wire “hanging”, you can bet the module and coil have had their service life compromised. How much depends on how long the wire was “hanging”. To properly disable the ignition system on fuel Injected engines, with the key in the OFF position, unplug the crankshaft position sensor, remove the ignition relay or unplug the J-1 and J-2 connectors from the ECM before cranking the engine. On carbureted models, unplug or remove both connectors or wires from the ignition coil or unplug the distributor. This will prevent starting a fire by removing all spark and fuel (injected engines) capability from the engine.
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