How do I fix

If a misfire is bad enough the cpu will shut off traction control causing the light to come on. For the engine light to be flashing you need a heavy miss and shouldn't drive it due to potential Cat failure. Changing the coil can fix all issues if that's the only part causing a misfire, typically i would recommend changing the spark plugs while you are in there.

Hello and welcome, when the check engine light flashes, this means a engine miss that can cause damage to the cat. converter if you keep driving, you will need to have the system scanned for trouble codes, probably has a code P0300. a engine miss can be caused by spark plugs, plug wires, ignition coils, injectors or even a internal engine problem

The blinking is due to the hard misfire. I would check the spark plugs, coils, and wiring to the coils. I would also test fuel pressure.

Try replacing the spark plug wires set.

Number three cylinder is miss fire,it does not mean it is the coil,although it could be,remove the coil,and boot,and spark plug,inspect them to see if the plug,or boot look bad,replace the spark plug,and if the boot is burned or distorted,replace it,a fuel injector can cause a miss fire also,but change the spark plug and see if this solves the problem,if not replace the coil,if it is a dead miss,then the coil might be bad,as for the water in the fuel ,the cap is missing,,and 5 dollars worth of HEET will not hurt,also,fuel from the fuel station,can have water in it.It happens a lot.

you should have the vehicle check to see if there is any code then you can go from there.
if the check engine light flash that meant you have a miss fire

put a screw driver into the plug that you think is missing get it one forth of an inch away from a good ground and crank the engine over if there is spark try replaceing the plug or plug wire or both, and if there is no spark if that model has a distributor replace the cap and rotor and wires otherwise if it has the coil pack you will have to change the coil pack.

Change the fuel filter and pressure regulator, restart the computer.

Either a bad plug, dirty plug, bad plug wire, not quite broken wire, bad or going bad coil, dirty injector. I would reset it first and make sure it comes back. If it does I would check the aforementioned items first.

Thanks for using FixYa!

JC

Check the plug and plug wire to #3, if they are ok test the fuel injector and test the compression on that cylinder.