my experience with the accent misfires and coilpacks
just passing on some info. thanks to rocconi for putting me on the right track, i think its the damn plugs after all.
all this is my theories and will be proven yet either right or wrong...time will tell.
SHORT STORY: gap your plugs for 0.035" instead of the recommended 0.044".
ok so i was having the common missfire from my accent (1.6L) as many of you have had. often the coilpacks get blamed. i no longer think this is correct. its my belief that the recommended spark plug gap of 0.044" is incorrect for our coils.
so at first i used the NGK V-Power plugs (v cut electrode) gapped to 0.045" - i have a wire gapping tool so 0.044 isn't an option. worked fine for a few months then the dreaded misfires began. i assumed coils but all testing showed them to be in perfect health. same with the wires....
rocconi mentioned to me in another thread that he had used NGK Iridium plugs and gapped them a little tighter than the 0.044". this seemed to solve the problem for him. this got me thinking...no way in hell does a piddly little 1.6L engine require a high end spark plug like the iridiums. not saying its a bad idea, i just feel its unnecessary. if you want them for performance or other reasons, thats different.
from what i understand simply plopping in iridium plugs will reduce the needed voltage to create your spark by approximately 5000V. this is due to the fact that iridium is an excellent conductor close to that of copper and the ability to make an insanely small tip on the plug due to the hardness properties of iridium. simply put, you get a bigger spark with the same gap compared to copper.
this brings me to think that the problem is not the coils, wires or plugs - its the plug gap. smaller plug means less voltage required for the electricity to arc over that gap.
to further confirm this all my old plugs (used about a year only, same ones) have a good coating of soot indicating that i'm either running rich (not likely in an unmodified car with no error codes from the ECU) or the mixture is not being burned entirely. that would be my misfire. upon inspection my plugs had a gap of closer to 0.050". thats slightly out of spec but not by much here. OEM equipment SHOULD be able to create a spark with this. that then leads me to believe that the OEM coils are rather weak and hyundai is really pushing it with that 0.044" spec on the plugs.
the coils simply do not push out enough voltage for the specified plug gap.
end of the story is new plugs with a tighter gap - i used 0.035". the results are a MUCH more responsive throttle and no misfires! YAY!
within the next couple weeks or even months i'll keep an eye on my plugs for any soot deposits. if they are pretty much gone, then i think i've got the problem solved. i'll post here with my findings. i put a lot of miles on my accent so i think i should know sooner than later.
also i intend to check plug gaps every 6 months now as opposed to checking every year.
just my take on this seemingly common problem, feel free to think i'm full of shit. thats a possibility anyways.