Hi all,
I have recently acquired a 97 Mark VIII. The car was idling rough so I performed the following trying to eliminate the issue:
1. Replaced the air filter with K&N, the old filer was so dirty that it was black in color.
2. Cleared the MAF
3. Cleaned IAC
4. Replaced the plugs.

Here is what I did not do yet:
1. Did not clean the EVR
2. Did not replace the fuel filter.

I have replaced the air filter yesterday and drove the car for about 30 mile and it drove fine but the rough idle was still there. Today in the morning I started the car and it was running much, much, much worse. The engine was revving up and down by itself and the whole car was shaking pretty bad. I though that the oil fumes in the K&N have messed with the MAF so I removed the filter and replaced it with an OEM one and cleaned the MAF again but the problem is still there. When I replaced the plugs today, 2 of them were covered in black oil, just the thread. See the pics. Help me out guys, what could be the cause of this bad idle. Thanks in advance.

http://images5.theimagehosting.com/eng01.jpg

http://images5.theimagehosting.com/eng02.jpg

How many miles? Original wires and coil packs?

Boots cracked on the coils?

Opps sorry guys, the car has 86000 miles and the boots were not cracked on the coils. I am taking it to the dealer on Monday for diagnostics cuz I ran out of ideas on what’s wrong with it.

I just realized it's a 2nd gen, sorry

Hey guys, just wanted to let you know that a set of new coil boots did the trick. Thanks for your help :)