Your TFI is located under the air filter box on the passenger side inner fender apron.
I had the same problem this last week. It was my pick-up coil inside the distributor. This is other wise known as the Hall Effect Sensor, pick up coil, or the PIP module (Program Ignition Pickup Module). It is a little difficult to replace the module sence you would have to take your distributor apart but the part is pretty cheap, only about 30 bucks from Autozone. I just decided to install a new distributor. You can pick one of those up (it will be a remanufactured one) from Autozone for about 150 (but you will get about 65 bucks back for your old distributor for a core, so it is like 87 bucks and tax).
Here is a copy of my post on my club site, it pretty much describes everything I went through, so check it out and see if your car is doing the same thing.
http://100mphclub.com/community/viewtopic.php?t=7185
Hope that helps, if you need anything....holler.
PS...if for some reason it is your TFI module, which it probably is not. contact Performance Distributor in Memphis. They sell the Dynamod for 65.00 and in my opinion is the top of the line TFI module you can buy, besides Autozone sells theirs for 60.00
