Toyota Repair: 92 Camry Stalls after running for 10-15min, tps sensor, camrys

Question
Bought 92 camry lastweek. It was running fine for couple of days. After that when It runs for longer it stalls and at that time it is hard to start and even if it starts it stays running only if I keep pressing the gas. It got worst. I took it to a shop and did a major tuneup. They checked in the computer and they put a used throttle that comes with sensor (idle). After that I had to change the starter. I took it to a different shop. They tookout the old alarm system thinking that was causing the problem. And then they checked the vacume leak externally with the fuel injection, checked the fuel pressure, spark. Since the spark was low, they changed the distributor. Now it got little better, it runs about 20-25min and than it stalls. They put it in the computer and it shows only problem is the tps (sensor adjasent to the throttle). They said the idle may go up and down, however, it should run. They'll replace that sensor again. But I still have the same problem. So far I spent $1450.00. Can you tell me what should I do. Does it look like anything with the computer or fuel injection. Please help. Thanks

Answer
Some Camrys have this stalling problem because of a malfunctioning idle speed control valve, it is located on the throttle body, I'm not sure what was replaced based on your description but the problem is that the valve may be hanging up and and causing the stalling, the solution is to either clean or replace the ISC valve, not sure this is what is going on but it is a common issue with Camrys.