Starts but won't idle
 

I have a 1999 328ic convertible that is driving me nuts. I put the car up for a few months after removing and replacing the carpet.(quite a job if you've never done it before), anyway, After bringing it back on line I drove it a couple of days when on my way back to the house it started running like it was running out of gas. After that it would'nt run. It would start,but only for a second or two. I thought it might be bad gas, so I changed it as well as the filter. No change. I put an injection test gauge on the rail and found that fuel pressure was building up only to find out it would drop off when the engine would start for the few second it did run. I changed out the fuel pump and fuel pressure regulator and it was holding pressure after a start attempt. still no change. I know the injectors are good because for the few seconds it runs it runs smooth. I have disassembled the intake system up to the manifold, inspected all the vac system, cleaned and ohm checked the ICV. I reinstalled every part with care to insure there are no leaks. I am stumped.
Is there a run circuit in the system I'm missing or something. I'm having a hard time associating a carpet change with this problem.
Any help would be much appreciated. :wtf

Check your MAF and your throttle position sensor as well.