I have a 2003 GMC Sonoma, 4

I have a 2003 gmc sonoma, 4.3. The truck starts when I add fuel to the throttle body, but other than that it won't start. I've changed the fuel pump and filter, and it still won't start. I've also removed the Pleum to see if the the injectors were working and they worked. I do have spark since when I added fuel to the throttle body it ran. I did have a trouble code PO101 on my OBD2. I'm in the proess of cleaning the MAF sensor to see if this helps the no start. I've also checked voltage to the crank shaft sensor and MAF sensor. I have correct voltage. I also did a fuel pressure test today and it's 60psi key on. As soon as the pump stops after 2 seconds the guage drops to 55psi. It holds pressure for five minutes at 55 psi. Cranking psi is 59. Any suggestions? Thanks!