Hello i have a 99 elantra and the engine is running rough. I thought it might be a spark plug or some thing, or a coil. so with it running i pulled #4 cylinder plug wire and the idle didnt change although there is spark, then pulled #3 almost died same with 1 and 2. could there be a possiblity that the cam shaft sensor or crank shaft sensor is bad or could it even be worse like the timing belt or chain not sure what it is. the car has 108000 miles on it and its probably been through the hands of many. So please help anything helps Thanks im a newbie

 

sounds like #4 is misfiring. ECU most be storing codes at this point, we need those to do anything more.

 

If the check engine light (CEL) is blinking while its running, its misfiring. The code stored will probably indicate a misfire in cylinder #4. Are you sure you have spark coming through that wire? Try swapping out another wire and see if that fixes it. What does the plug look like?

 

Thanks for getting back to me guys, I will try the spark plug wire swap. But yes there is spark comming from that wire it sparks until the thing is completly removed from the valve cover. do you know where i can have the codes removed or i should say read. Also the check engine lite is on solid with no blinks i think the only time it blinked was when the spark plug was removed and running and yes i had good spark out of the plug. So any more ideas, im soaking every thing up

 

Most of the chain auto parts stores (auto zone, advanced auto parts, etc) will allow you to borrow a code reader for free to read the codes in their parking lot. Find out which codes are stored in the computer and post them here. It could be any number of things. Bad wire, bad terminal on the coil pack, maybe a malfunctioning sensor but its hard to say without the codes.

108kmi is young for this car. Though, if you have no idea when the timing belt was last changed, I would get it changed.. yesterday. Replace the belt and both pulleys. Maybe the water pump too while you're in there. I know the recommended service interval for my '97 1.8L is every 60 kmi. I'm not sure if its the same for your '99.