if you are taking the timing cover off, you may as well just replace the timing chain regardless. believe me, you dont want to take it off more than once. (in the car anyways). and i would also recomend replacing the tensioner(dampener). total cost for parts and gaskets should be about $100.

ps, it is BEST to drop the oil pan after everything is back together. it is quite suprising how much coolant you will see, even after draining the pan.

Nice write up. I especially like this quote:

There is a way to check for slop in the chain without taking the cover off -- take the oil pan off instead. You can see the bottom of the chain and you should be able to check the tension of it just by poking on it. Also, you can check for debris in the oil pan such as broken tensioner parts which would also mean that its time to replace the TC, gears, tensioner, cam magnet, etc.

And if you do need to replace the TC, you really should pull the oil pan anyway as already mentioned.

A bad tps signal could also effect ignition timing. Check the voltage in the idle position.

Just as a side note even that step isnt really required... I did my entire timing job just by driving up on ramps. I braced a good quality 1/2" drive on the frame of the car, hit the starter to loosen the bolt, then removed it. Putting it back on is harder, but I am 330lbs and 6'4, so with a 24" breaker bar Im fairly sure I got it back on there with at least 220 ftlbs.
Timing chain jobs on a VinC of these years is actually fairly easy.

I have a Grand Prix that back fired once and I coundlt restart it...The Ignition control was to blame....Unless your engine is slap worn out, I'd be hard pressed to replace the timing chain unles you lost the cam sensor magnet...

Was that GP a 3.1L? Same thing happened to me... damn chinese ICM units... thing lasted me ~500mi and left me stranded of all places; autozone.

At least you were at the Zone......AUTO ZONE!!!! "BUILT TO LAST!!! DURALAST!!!!" hehehe......

Actually it'* the car in my signature 3.4, they use the same controller as the 2.8, 3.1, 3100, 3400....That died on me after a job interview..I went o get some lunch ant the McRonalds and i got back in the car and restarted it and BOOOMM!!! I had my laptop and my ALDL cable so I was able to do a few tests....Luckly I had a friend about 30 miles away that had a spare controller, coils and tools.. I had to change it in the parking lot. Luckly I had a change of clothes...... I was 80 miles from home.....Friggen engine....I had to sit out there for hours till my friend could make it down to me....