I just took my 94 Thunderbird for a trip to FL. I put around 4000 miles on the car. The odometer currently reads roughly 117,500. Car was running perfectly. While down there (I was visiting my father) we replaced the TPS and EGR valve (no reason), checked plugs, cleaned trottle body, charged AC, and changed the oil. Everything was running fine for a few days. Then the night before I left for NJ, the trouble started...
We got 12 qts of Mercon V, filter, and 1-2 accumulator piston. We drained all of the old fluid (looked great). The old 1-2 piston came out with some trouble (the previous shop had beat the crap out of it putting it in - never seemed a problem though) and we replaced it with the new rubber unit. We reused the old gasket since it was in good shape, replaced the filter, and added 8 qts of Mercon V. I shifted trough the gears and noticed that the engine started running a little rough. I thought that this was going to fix itself once I added the rest of the fluid. So we added the rest of the fluid, ran it through the gears, and went to bed.
I woke up the next morning and started the car. It ran like crap! It would seem to try and stall itself then shoot up 300 rpms (about 900 rpms in park) and then go back to stalling itself out. Same thing in any gear. AND I HAD TO LEAVE IN 2 HOURS!
So I took it for a test drive. Everything seemed ok enough when I was accelerating except for a small hesitation, almost a stumble, then it would pick itself up. Then it through a code. I took it to autozone and it had something to do with the air/fuel mixture (don't remember exact code). So I drove it home. By this time the car was running even worse. Checked fluid level which was perfect. I called my dad at work and he told me to get the thing checked out before I left and then chance the trip. I took it to the local shop and they suggested that the TC didn't like the synthetic fluid and to change it out for some new Dextron. Since he said this without me mentioning anything, I just went for it and left. Problem got much worse but the car made the trip.
The car didn't maintain speed too well and had a terrible shudder especially at lower rpms (under 2500). Once I got home the car would barely, I had to almost floor it, get up hills. Even when floored the rpms, however, stayed constant. The reason I think it is in the TC is because everthing was fine until we touched the trans. It feels like the car is slipping (only with a horrible shaking) and then it catches and takes off as well as smoothes out.
I'm in high school which means a couple things. I NEED MY CAR BACK (I won't drive it til I get it too a shop, I have a feeling it won't go at all pretty soon)! I also don't have too much money. So I need to narrow down this problem. I do have some decent automotive skils but if it's the TC, I'd be much more comfortable with someone else doing it.
I'm open for any questions/suggestions/comments....ANYTHING! I need to fix this asap. Sorry for the long post. WHY WOULD THE MERCON DO THIS! AHHHHHH!