japan4racing

so i developed a misfire situation but it was very intermittant..it got real bad the other day so i started searching the forums here and and at the mach1reg and found a few helpful threads. come to find out i had water on the back 2 coilpacks on the right bank. i didnt have plugs to toss in at the time so i just took a air hose and blew all the water out, thoroughly cleaned the coils (they were filthy where the spring makes contact with the plug) and checked the coils to make sure they were good...i pulled all 8 and checked them all and they are all good. after i reinstalled the coils and fired her up a puff of smoke came out. so i thought maybe that last coilpack that was really dirty and watery wasnt fireing good the whole time and now it fired good and burnt off some excess fuel/whatever becuase the car has never smoked before. took her for a spin and at first it seemed like it was fixed then it started again...dammit!

today i pulled the plugs and none were terrible looking. there was no signs of lean conditions..some looked like they had some fuel on them but overall they looked ok. they were all gapped between .054 and .056. i put some ap104's in gapped at .054 and went ahead and changed to fuel filter. so far so good so i have my fingers crossed that its fixed now.

now onto the question...i have had alot of turbo honda's and mazda's and i would beat on them regularly...so for that reason i changed plugs alot. i would use iridium or platnum plugs at the beginning but they fouled so easily that i just went to a standard one step colder ngk plug and never had problems ever again. so if this problem comes back is it possible that im fouling some plugs and maybe i should just go to a standard plug. i have always liked ngk plugs and would run nothing else but i went on some recommendations of some guys at work and got the autolites for the stang. i wouldnt think that it would need a tune since it only has a catted x-pipe, magnaflow cat back, and small intake mod. is there anything else that would cause the stuttering? i run 93 octane only so its not that im running cheap fuel either...im just gonna be lost if this problem comes back now that i know i have fresh plugs, good coils, new fuel filter, and 93 octane. thanks guys for putting up with my newb questions!

meechuacon

I'm using the NGK stock replacement plugs for my 03 mach and haven't had any problems with the plugs at all. I did have a bunch of problems with my coil on plug set-up. You may consider replacing a couple or maybe all of them with motorcraft stock replacements. Trust me the the motorcraft are the best. I tried the Accel and the Granatelli aftermarket ones and I would get a miss with those as well, even though I checked the resistance and all were the same. Replaced all with new motorcraft, haven't had a problem since. So I recommend replacing all of them.

meechuacon

Oh, and be sure to use RTV around the coil covers. Especially around the loom that the wires go through. Moisture gets down in the back and ruins the no.8 coil pack. My valve cover actually had corrosion down the hole of the no 8 plug. Do it right the first time and you won't have problems for a long time!

japan4racing

well since i changed plugs the problem has not returned...that #8 was the main culprit...i think its fixed now (crosses fingers) got 22.7 mpg out of my last tank of gas too! i almost bought the aftermarket cop's but after reading about them on this site and on m1r i decided against it. if they end up needing to be replaced i have no problem what so ever useing motorcraft. i still need to re-seal the covers though...thanks for reminding me!

japan4racing

it returned the other night..it started raining 2 days ago and it start misfiring with the rain. i pulled the #8 cop and no water, i checked resistance and they are good..the more i drive it the worse it gets. im getting pretty pissed...it has new plugs, new fuel filter, i only run 93 octane, and all the coils check good what could it be? is it possible that they check good but are bad somehow? im very confused

USMCrebel

you could check the coil packs, BUT i haven't heard of to many coil packs going bad like that. did you change the wires as well? after time the rubber wears down and can cross jump and cause misfires. i had this problem in my 67 stang, and in my 98 escort

japan4racing

the only thing i have changed is the plugs and the fuel filter. it seems to do it really bad when its raining..this last time it did it i pulled the cover off and took a look at the coils and there was absolutely no water in there. under load it does it bad in the rain. i ordered a new coilpack for the #8 since that was the one that had all the water on it the first time. its just really weird...they check good but they act up in the rain with no water on them..maybe one of the boots is allowing spark through and its shorting to the head....hopefully i can find it soon cause its really annoying.

I G Joe

i bet you have an exposed wire or connection on the back of the motor somewhere, when it gets wet it grounds out.

when its a nice dry day, try opening the hood, spraying a part of the engine and take it for a drive around the block, see if it acts up.

japan4racing

hmmmm...i will look into it..coil came it today and i already installed it. maybe i will take a look sunday when i finally have a day off

USMCrebel

shoot you gots to make time for a mach 1