The engine may fail to start due to an electrically shorted sensor. Some of the sensors may internally short and not blow any fuses. A technician may find no spark and no operation of the fuel injectors in the diagnosis. One way a technician may isolate the defective sensor is by disconnecting sensors one by one to see if the engine starts.Google+
Car Problem Reports
Mazda B2500 Crank but No Start Condition and No Spark
Mazda B2500 Problem
Engine Affected: 2.5L 4 Cylinder
Visitor, 1998 Mazda B2500, 2.5L 4 Cylinder
Truck would turn over fine but not start. Next day, no problem. Next day same problem. Intermittent for about a week,then totally would not start. Had no spark.