98 PA transmission shifting

The tensioner pulley on my buick siezed up and went flying somewhere throwing off the serpentine belt and flinging it around. After getting it all put back together the car started up fine, but it had a few problems that were not there before. I took advantage of working on the car and put in some new spark plugs and a new fuel filter. Now when I put the car in reverse, it kicks like a mule while shifting. I noticed that the RPM's are higher while in park, about 1200 and they used to be about 600 - 800. The odometer has also quit working. Is there a part anywhere that the belt or pulley could have hit and damaged that would cause this. Another note on this is that the new spark plugs are the ones that you do not gap and the old plugs were the type that you do gap, could these "hotter" plugs be causing the faster idle?
Thank you for any help.

The fast idle is the clunk in reverse of course. Not being there to see what may have happened when the pulley came off makes this difficult. Check the connectrors on the transmission for starters, look at all the sensor and harness connections around the engine also.

Thanks for your answer maxwedge, I probably should have given a little more information. The new spark plugs that I had installed were Bosch platinum 2. These are apparently hotter plugs than the buick could handle. I disconnected the battery hoping that the computer would reset and recognize the difference, but with no luck. I then went to an autolight platinum plug that was not as hot as the bosch and reset the computer. This time the RPM's dropped to about 900 which is still a little high but the shifting was almost normal, after the car warms up. To my knowledge there is no way to control the RPM setting, is this correct? Does anyone out there know how I could get the idle speed to drop to 700 RPM's. Thanks.

To my knowledge there is no way to control the RPM setting, is this correct? That is a correct statement for the average DIY'er.

Does anyone out there know how I could get the idle speed to drop to 700 RPM's. Thanks.Is your PA an Ultra, or base? Sounds like a slight vacuum leak, have you checked all vacuum hose & fittings?

Just a side note here....

Never, Ever use Bosch Platinum Plugs in any GN Waste Spark System.. Glad you changed them out to autolite..

Next to looking at all of the wire to make sure everything is intact, it may help to know what the PCM is seeing to determine if there are any other issues its trying to correct for..

Thank you HotZ28 and Jrs3800 for your input. The Buick is the plain Jane not the super. I haven't found any vaccum leaks, but the car seems to be running ok if I let it warm up enough before shifting into gear. I do however have 1 more problem, the speedometer somehow was affected by the initial tensioner pulley incedent. According to the computer codes I either have a bad speed sensor (there are 2) or a bad gear. Does any one know the exact location and how to get to and remove any or all of these 3 devices? Also, is there a way to tell if only 1 of them is bad, besides trial and error?

You only have one vehicle speed sensor (VSS) and it is located on the passenger (back) side of the case. (See Pic) Evidently the "flinging belt" damaged the wiring or terminal connector on the sensor. Check all possibilities here first. BTW, you have ABS 'wheel' speed sensors, but they have no input to the speedometer.

http://img171.imageshack.us/img171/9315/4t60e.jpg

Thank you HotZ28, weather permitting I will look at that tomorrow and will let you know the results when I can get back on the net.

Thank you very much HotZ28, the picture was great, showed me exactly where it was. I guess the device got hit by the belt and became unplugged. I plugged it in and the speedometer works fine. Then I disconnected the battery and recconnected it, per your instructions to a different thread, to reset the computer. After restarting the vehicle 3 times and driving about 1 mile the check engine light went off. I am finally back on the road, thanks to all the people who answered my problem it really helped.