Which engine?
During a no-start event narrow the problem down to fuel delivery or ignition - if the engine will briefly fire with a shot of starter fluid into the intake then it has spark but no fuel. If the spark plugs are wet and the engine won't fire at all it's probably an ignition problem.
Have you ever had security system troubles - that can lock out either/or ignition and fuel.
During a no-start event narrow the problem down to fuel delivery or ignition - if the engine will briefly fire with a shot of starter fluid into the intake then it has spark but no fuel. If the spark plugs are wet and the engine won't fire at all it's probably an ignition problem.
Have you ever had security system troubles - that can lock out either/or ignition and fuel.