1998 mazda millenia will not crank

That is because you have destroyed the engine's electronic control unit and heavens knows what other electrical systems on the car.

If the engine overheated and now won't crank, you may have locked it up. If you can't turn the alternator or the crankshaft with a wrench, the engine may be trash.
One of the cylinders could also be full of coolant from a blown head gasket.

Misfirng...

1998 Mazda Millenia S 2.3 liter DOHC V-6




1998 Mazda Millenia L 2.5 liter DOHC V-6




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Try jumping the starter i.e use a starter manual switch. If it cranks than most probably you have a faulty switch.

Spray some starting fluid in the intake Manifold this will give it a jump. Good luck

If your car ran hot, you may need to check the radiator for a leak. You always need to add antifreeze/coolant when you add water to your car. Check you owner's manual for the type they suggest and the proper mix of water to antifreeze/coolant. I had to get a head on my motor shaved when my car ran hot and later I had to get the hoses replaced. My radiator cap died following my replacing the radiator as it was plastic and when the car overheated it damaged the cap. How long was the car running hot? You don't want to be a penny wize or a pound foolish when it comes to engine overheating problems. You can repair on the cheap now and pay a lot more in the long run. Also, in the future when your car runs hot, you can turn on the heater --yes even when it is hot outside--I recommend opening up the windows. The heater fan will help to dissipate the heat from the car engine. It does work. I hope these help. Also go to a reputable repair shop. It could be your thermostat they can have check valves which get messed up but you need to check to see if it is your radiator or if there is a leak there or in a hose.

fuel filter would be the first thing to check, and fuel pressure.

sounds like a dead battery to me maybe even a dead cell in it? check that first, get back to us.

Hopefully, it is a mis-timing of the ignition and not an improperly installed timing belt or chain. The latter cold be fatal to the engine. I suspect that was not a cheap replacement so I wouldn't delay having it checked. 

I Suspect the timing belt has jumped, this usually happens on cold start if the belt is ready to go. How many miles, are you over the recommened change mileage?