2005 Mazda 3 Repair Question
Mazda 3 overheated - won't start
The engine will still crank without any unusual sounds, but will not actually fire. We have ordered a new radiator. Is there a safety system that might be preventing the engine from starting until it is reset?
Answer
It doesn't have a fuel cut off switch like a Ford-check for fuel and spark-Do below
Cranks but no start condition:
Get a helper disconnect a sparkplug wire or 2 and ground it to the engine at least 3/16 away from ground -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem,Do you hear the fuel pump come On when you turn key on? If not check fuel pump fuse and fuel pump relay if so, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard i
further info --
Car does have both spark and fuel, but 2 different compression tests showed zero compression. When cranking the car, engine seems to spin very easily (just like other cars that I have owned in the past that had a broken timing belt) -although the timing chain seems fine and the camshaft is turning when the engine is cranked.
Time to open it up and investigate the valves/rings/cylinder for wear to include the timing chain -could be stretch/jumped time