Well, I just got a tune-up on my '97 Trans Am. The thing ran like a champ the first few weeks of spring and I put her away for about a month and I got her out a few weeks ago, stumbling and misfiring all over the place. I ended up getting new plugs and wires for it (TR-55s and MSD Super Conductors). The car was done about a week ago and I picked it up and drove it around downtown. She was fine until I hit the highway to go back home and she misfired once then kind of felt like it had some power loss again. I turned around, drove it back to the shop, but in town the car drove just fine. I went back to the shop, the machanic cleared the codes and we took it for a drive through town and then on the highway...nothing went wrong, no codes went off. I drove it home and the car was fine as well. At idle, it sat around 600-700 rpm and studders a little bit, but nowhere near as bad as it was before, probably a 75% improvement. Eventually it just started to get worse and worse. Now I can barely even drive the car from my car to the shed which is about a 1/2 a mile away from my house. It starts up right away, no big hesitation there. I have a scanner and it reads P0300 which is multiple cylinder misfire.

I'm just trying to figure what is going on with this car. The mechanic said there was a little bit of carbon build-up on the cap of the distributor, but nothing to be worried about and my coil was fine. There are many possiblities...but I don't want to go replacing stuff without getting some input. I'm starting to even think he might have bumped the timing just a little and it is continuing to get off or he just put wires on the wrong order at the distributor. Gas is literally shooting ou the back onto my drive whenever I run it and it is popping left and right. What do you guys think?

 

Oh boy...


Well first of all how do you "bump" the timing on an opti car? Not like they have an old school distributor hold down that can get loose..

2nd did the mechanic take off the opti and look at the cap and rotor? That's a hell of a big job, probably taking about 4 times as long as a spark plug swap... He made it sound like he popped the cap off the distributor, looked at it, and put it back on all in a matter of minutes. Again, not possible on an opti car.

3rd, even if he DID take off the opti cap and inspect it (which there's a 99.9% chance he's lying about) how the hell would there be "carbon buildup" inside a distributor, where nothing that would ever form a carbon buildup is present... Carbon deposits come from things that have carbon burning inefficiently and leaving it behind.

4th if the .01 chance he's not lying is entertained what he's calling "carbon buildup" is actually burn marks from the cap/rotor assembly arcing out. In short the opti is dying (assuming he actually saw dark discoloration on the cap and rotor, inside).

5th, I don't see how it could be him "wiring up the wires wrong" because you drove it after the codes were cleared and it ran smoothly. Then you said it "gradually" lost power. Kinda hard for plug wires to get wired up wrong "gradually".

I would bet your opti is dead, but that's just a wag without any diagnosis.