Check engine light onn when i hit the gas it blinks ..im getting miss fire code on multiple cylinders new coil ,new wires ,new brain,new cap rotor and sensor

When light is blinking not good exhaust system usually catilatic converter blockage in system. Causing the hesitation. Go to autozone and get a computer reading obd that will tell you. Be careful driving it

HARD TO SAY WITH OUT BEING THERE BUT THIS MIGHT HELP .
Crankshaft sensor Was the trouble with my 99 Chevy truck after replacing many components like coil cap rotor wires and so on .
http://www.obd-codes.com/p0102 Code P0300 Causes and Fixes Code p0300 is a code that is generated when your engine has a misfire that is not related to only one cylinder. Sometimes this code will be set in addition to other codes such as p0301 which means that there is a misfire on cylinder 1 (cylinder 1 is the number one cylinder when looking at the firing order. It is generally the forward most cylinder on the engine.). If these engine codes are present as well the you should diagnose those first as they are probably causing code p0300.
This code will set your check engine light and needs to be fixed as soon as possible. If it is not then you will probably need to replace your catalytic converter as well as the problem that is causing your misfire.
There are many causes for this obd code. Since it is a "random misfire" or "multiple misfire" this means that the misfire is on different cylinders and not just one all the time.
Common Causes

• Low Fuel Pressure
• Vacuum Leak
• EGR system malfunction
• Internal Engine Problems (such as low compression)

Less Common Causes

• Faulty Coil
• Faulty Spark Plugs and/or Wires
• Camshaft or Crankshaft sensors
• Ignition module
• Computer

replace the injector in no 2 cylinder

The cat coil, and engine module could be bad.

Got a check engine light? Get the codes read to find out if the misfires are on all cylinders or just 1. Could be ign coil, bad crank or cam sensor, or a valve issue

You put something back the wrong way.....any amount of water in the tank, carb or whatever WILL NOT cause the engine not to fire.....check any wiring/rewiring you did for accuracy

check valve adjustment on #5, is cam lobe worn?

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.

ignition coil or firing order incorrect 1-3-4-2 is the firing order go clock wise on cap in that order

You have a cylinder misfire. That is the only thing that will flash the check engine light. With the van running spray the plug wires with water. Watch and listen for arcing. If there is, replace that or all the wires. It is possible for new wires to be bad. Next check the cap and rotor buy spraying them with water, than removing and looking inside for signs of burning or anything that will hinder the spark. Last check the spark plugs for carbon tracking (small black lines in the porcelin), caused buy hair line cracks. If you dont find any thing, check it again. With no other codes it is very unlikley that anything else is causing the misfire.