GM-GMC: 2004 1500 Chevrolet 4.3 V6, mass air flow sensor, mass air flow

Question
The truck quit while driving and would not restart the only code was Mass air flow sensor, we replaced the sensor and the truck started and ran fine for 1 day. The driver stopped to get gas later that day and it would not restart, we have replaced the coil and the crankshaft sensor and it still will not start.We have voltage going to the coil but no spark at the coil wire while cranking the engine. Any ideas would be appreciated

Answer
My first step to diagnosing that problem would be to check for cranking rpm.  That can only be done using a scanner.  If the engine shows cranking rpm most of the engine side sensors are functioning.  After that I would check the cap and rotor.  Those engines are notorious for fowling the cap and rotor resulting in a no start condition.  If the cap and rotor check out alright double check the coil and that power and ground going to it.  Aside from that I would begin looking at any theft deterrent systems that the vehicle may have.
Hope this helps.