We just got done installing a refurbished supercharger after we heard the blades slapping and discovered ample amounts of oil in the intake and inter-coolers (lots of oil blow by) but even before this install we had a cylinder misfire on #3 we changed around coil packs and have looked in to the basics as far as a miss fire goes, so at this point i'm not sure what it could be. I have searched this forum and found some slightly helpful threads but i'm still kinda in the dark. The symptoms that we are experiencing are: Smooth idle in neutral and park. In reverse or forward gears the car shakes and idles rough, driving the vehicle over 30mph the car smooths out and becomes drivable with out any misfire i assume this is due to timing advance? basically in a nut shell any type of load the engine experiences it runs rough and shakes. What are some things to look into or type of trouble shooting i could do being that the NEW coil packs are slightly more then I'm willing to spend are there any other models or makes that carry the same style coil pack that i could use from a parts yard? Any help would be greatly appreciated!

 

go to mazdaworld.org, you will have to register. then go to the millenia section, look for bigb. he just dismantled his car, has a set of coils, and a bunch of other parts. too bad, he has a pse reman compressor.
is the ce lite on? if so, what codes(and the actual NUMBER, not someone's interpretation) are there? present the codes also on the other forum. look for a post by saint for how to test the coils. i have experienced a weak coil, but the symptoms were opposite of yours. car started and idled smooth, but under load, esp at higher rpms, i would get a slight miss. since we have 2 99's, and no ce lite to id which cyl, i first swapped out the front bank coils to the other car, and sure enough, the miss followed. i then started changing coils, after the second one, the miss was gone. again, ce lite never illuminated, so i had to guess. i am just glad it was not one of the rear coils, since they are so hard to get at. over the years, i have acquired more than 2 sets of coils, a couple new ones, because of the failure rate.

 

You mentioned you swapped coils but did you test for voltage? And what about air & fuel. I'm thinking that's where I'd be looking next before throwing parts at it... you had the intake apart when you replaced the SC so start by checking for a leak at the intake runner for cyl 3. Unfortunately 3 intake runner has a lot going on around it, so there are a few potentials for vacuum leaks that could show as misfire 3.. easiest way would be to shoot some brake clean or starter fluid at the manifold/head joint, intercooler/manifold joint & the joint directly above it where the upper intake section bolts to lower intake 1-3, while its idling & see if the RPMs change, also try to shoot some at the injector seal since you likely had them out as well. If there was a small vacuum leak it would explain rough idle (un-metered air), then above 30mph (under boost) it smooths bc air velocity is greater than leak rate... Hopefully you find a leak at one of the easy to get to bolting points and you don't have to go thru the task of removing that ridiculous Miller Cycle intake...