Before you buy a rebuild kit.
You might wanna check a couple of things before you buy a kit and tear into your TBI. The fact that you say you have to "step on the gas to start it" indicates a problem with the mixture at cold start. That can be an issue with the MAP sensor, an oxygen sensor, or other sensors that send info to the "computer" . The chance that the starting issue is in the TBI itself, at least in my experience, is slim.
Also, most of these set ups have a brown wire that is disconnected when timing of the engine. It is usually either up under the dash behind the glove box or by the distributor at the fire wall. If that is discinnected your engine will not automatically advance the timing when in D or R or when load is applied to engine in general. Might be worth a look as well.