New supra owner (with a few questions)

[manrique112]

Good day Supra owners, i became a proud owner a few weeks ago. Since I do not know much about this car I will like to ask the experts for advice. Here is a link to the supra I purchased. It's a 1990 red,auto, turbo, targa top.
http://g35nyc.com/forums/showthread.php?t=36538

Here is a list of concerns.
1. engine looks like it was rebuild by someone inexperience and neglected to proper place the vacuum lines. There were a couple i found laying around.
2. car idle is bad. sometimes is steady and then it goes up and down.
3. car tends to stall specially when i'm at a light and when i make slow turns. (kind of scary)
4.The throttle body and TPS are of a non-supra engine. I was wondering if thats and issue.
5. Manual showed me to do a check engine scan. Codes 21,31,41 came out. TPS, MAF.
6. Should I replace the TPS even if the throttle and tps in the car is of a non-tubo supra.

Any suggetions will be appreciated. I will like to have the car up and running before May. Thanks.