Try using another GM pass key for the car.
Sometimes the ohms resistance / connection of the chip in the ignition is bad causing the car to die.

Try the new key as suggested. If this doesn't work we have to start from basics and work through this in a specific manner to ensure that we don't miss anything. That code that you had earlier P1640 is for one of the QDM (quad driver modules). These are simply that switching transistors within the PCM that turn things on by grounding the circuit. That specific one - P1640, on VIN 1 (SC) deals with the TCC (torque converter clutch), the EVAP purge solenoid and, get ready for this.... Boost Control Solenoid. This may have been the problem with the boost you had earlier, but i doubt that the boost control solenoid is causing the no-start here.
What we need to assess here is if it is the VATS (anti-theft) which would log a trouble code. Try another key...if it works then the problem was with the key itself.
If that doesn't work, this is a shot in the dark here, but if it is simply starting and stalling right away...press the throttle in about 25%. This is going to test the IAC (idle Air control) system. If it is not opening or the passages are clogged then it will start and run while the throttle is depressed (air is good). Careful not to flood the engine by continuing to turn the engine over with it not starting.
If this doesn't work you are going to need the codes scanned again to see what is logged. You may want a fuel pressured test done as well to see what is happening when the car is started and stalled. Try those things and let us know what happens.

Well I kind of feel like a fool right now but here goes.

When I changed the fuel pump, I put gas in the car, I dont know what the gas gauge read but I knew I didnt have much gas because I could see in the tank. Well I put the gas in and started driving, drove all day and acually said to myself " wow I am getting really good gas mileage"

Guess what, that was not good gas mileage it was a stuck or non working gas gauge.

Today I pulled the tank back off because I realised I was not getting any fuel, when I did I found a fuel tank completly empty.

I put gas in and it started right up.

NOW , I still have the no boost problem and I THINK the stalling problem. I drove about a mile to the gas station and on the way it killed, it didnt on the way back but I had it in the driveway just running and all of a sudden it just died. Like someone shut off the key, maybe it still is the key like you mentioned that is giving me troubles.

I did some checking on the boost selonoid and PCM but I am not sure exactly how it is suppose to work.

I found that the pcm is suppling ground to the salonoid as soon as the car starts, I guess that means that when boost is needed it remove the ground??

When the car is running I have vacuum coming out of that selonoid and the boost lever is down close to the engine, if I remove the vacuum line the lever pulles up. Does this sound right??

I thought that I would hook a ohm meter to the pin on the pcm and see if I loose my ground when I floor the car going down the road

It is not the key issue if it dies after it has been running for a while. The check is only at start-up and will not affect an already running vehicle. You really need to get the vehicle scanned to determine if there are any codes present that may be an indication as to why it keeps cutting out. If it just simply cuts out light a light switch it is usually something electrical and not fuel related (counting injectors as electrical). Could even be something as simple as a bad ground but we do have to start at the beginning to rule out some things.

I am going to get the codes today, I will post results this afternoon

well I got the codes scanned. there were a bunch of codes. I think they were all garbage because I know I have a bad battery and almost everycode was something to do with lov voltage.

While I been spending all this time working on my car I would crank it over and the battery would go dead than I would charge it back up. So I am sure that is the reason for these codes to generate.

I put a new battery in and cleared the codes and am waiting for something to set. So far the car has had trouble starting 2 times, it does start but it seems like I have a shot at starting the first time and if it doesnt than its almost like it is not getting gas and just cranks, it always starts but I may 2 minutes or so. It also did a weird one on me, the traction control llight came on for no reason, it did not set the SES light, but I could not turn it off with the button. When I shut the car off and started it again it was off, and the traction control button worked again.

This thing is driving me nuts.

IT'* FIXED,

Can't believe it, I finially got it running, and its running great.

The problem was a bad Boost Bypass solonoid. This is one of the first things I checked weeks ago when this hole mess started.

I tested it with my ohm meter and it read open so I took it tio work one day to see if I could do anything with it. At work I hooked it up a power supply and found the relay working fine so I thought my cheap meter I have at home was broken. I put ti back on the car and continued my troubleshooting.

3 weeks later, I have the car running and I am looking at the engine and all of a sudden I see the solinoid do something strange. I checked it again and it read open, screw it, I went to the dealer with my ohm meter and got a new one, it ohmed out at about20 ohms. I put it on the car and it runns perfectly. has not stalled out once, on SES lights, great idle, its like a new car

Bravo, a little perseverence works once and a while. Don't you hate it when you spend that long looking for something else and it ends up being the first thing you checked. What do you care now, it works right!