New Owner of a 1992 PAU SC ~ Great Forum!

[uvalegend]

First of all, thanks to everyone for all the great knowledge in this forum!

I just inherited my father's 1992 PAU - Supercharged. It's a great car in need of a little TLC. It's idling rough when you first start and occasionally flashing the SES light. Last night I began to trouble shoot by cleaning the MAF, TPS ant TB per the DIY on this board. Great write up BTW... I also replaced the plugs, PCV, air & fuel filters.

I removed the IAC to clean it and determined it was hosed. After I finally got the pintle to move, I noticed a plastic peice inside was busted. I was a little surprised it was an $80 part at NAPA! This leads me to my first question...

1) How can I tell if the motor is design I or design II? The install instructions for the new IAC provide a different pintle setting for I and II. Is design I/II the same as Series I/II?

2) When I read the codes, it flashed code 12 three times like it is supposed to and then flashed the mystery code 18 three times. Then back to code 12 again. Anyone figure out what this code is? I found some talk about it, but nothing conclusive. The battery has been disconnected since last night, so hopefully I'll never see it again anyhow.

3) Lastly, what is fair selling price for the car? My daily driver is a 5spd BMW 735i and I have no business (not to mention room) keeping both of these large sedans, so the buick is going to have to go, eventually.

Here's the good:
- Supercharged and hauls a**!
- 106K
- Interior is in good shape. Leather is nice all around
- 2nd owner, very well maintained with all service records (several thousand in repairs w/in the past year or so). Including: Good Yoko Tires with 90% or more left, new brakes front/rear, new front wheel hub, new valve gaskets and main seals (I don't have the records in front of me, so I'm going from memory and probably missing several things)
- As of today: New plugs, air/fuel filters, oil change, IAC SENSOR, MAF/TPS/TB Cleaning.

Here's the Bad:
- It probably needs a wheel balancing and/or alignment. There is a slight wheel shake at around 65. The tires are almost new, so that might still be under warranty.
- the drivers side power window switch controlling the passengers window quit working. I cleaned it yesterday, but haven't re-connect the power to see if it works. I've checked ebay for a replacement switch with no luck. The motor is good and works fine from the passenger's side.
- Driver's side seat recline motor is stuck. Fortunately it's stuck in a comfortable driving position. I can hear the motor click when you hit the switch, but no movement. I'll soon try to get in and fix it.
- Headliner needs to be replaced. It started falling and my Dad actually cut it out behind the rear vanity mirrors. You don't really notice from the front seats, but it has been butchered.
- Large scuff on the front bumper. This was my fault! I traded cars with my dad back in 98 or 99 after having shoulder surgery (my car is stick).
Having very limited range of motion coupled with a bad blind spot in the park ave, I pulled into a slowly moving car in a parking lot. Oops! We never fixed it b/c it's only cosmetic and not that bad.
- Typical dings and scuffs for a car of it's age.
- The wheels are pretty dirty. Anyone recommend a good cleaner? I think they've been neglected for several years.

Well, that's all I can think of now! Thanks again for all the info!!!