Just wanted to add my little experience here as support for the "replace your ignition coils if they're ancient/if your 8 runs rough" recommendations that have been posted this year.

I knew the car had a minor ignition issue when I bought it, and I was happy and prepared to go through it with a heavy-duty tune up...did air filters, fuel filters, plugs, caps and rotors.

Wasn't until I opened up the exhaust that I could tell the right bank was noticeably rougher than it should have been. I was sure it would be plug wires, but when I checked the ohms, everything was fine. After putting the wires back on, seemed to get even worse on the right bank, with sputtering and popping, etc.

Well, got my coils yesterday, and problem is gone. From the looks of 'em, the old ones may have been the original coils...it's not too expensive and really easy to replace on the M70, so definitely recommend doin' em if you have oldies on.

cheers
:redspot

Good deal! Informative also, Thanks for sharing.

I was freaked it was something worse...think the whole neighborhood heard the whoop of triumph when I started her up to a smooth right-side exhaust yesterday!

:D

it's not too expensive[/COLOR] and really easy to replace on the M70, so definitely recommend doin' em if you have oldies on.

At $98 per coil, depending on whether it is an 8 or 12, it can be quite expensive, $784 or $1176! I hope my chance to replace them doesn't come up too soon.

Yikes, it is much more expensive for the later engines...
The M70 uses one coil per bank, at about $75 each.

One of the "problems" with trying to diagnose this is that even if the Ignition Coils "meter out" correctly, you really can't tell what they do under load, and that is where they fail. It is good preventative maintenance to replace these at regular intervals.

While on the subject of things seeming to "meter out" properly, could plug wires which give appropriate resistance readings still be no good? I ask because although my right bank has improved greatly, there still is a bit of unevenness to the idle. Hope to do throttle body rebuilds with Wuffer on Saturday in case that is contributing at all.

Also ran into that problem with my wires. Went with KINSBOURNE and they sucked (both sets straight out of the package). I wound up buying BERU OEM wires and haven't looked any problems, until the unrelated fire of course... :)

Will probably do blue Magnecores via Wuffer/Gerry to start up a blue theme under the hood, cheers!