Chevrolet Repair: Chev Tahoe stalling, fuel pressure gauge, chev tahoe

Question
Have a 97 Chev Tahoe which stalls and hesitates intermittantly.Have recently changed fuel pump and filter, pick-up coil(or whatever the technical name for that sensor is now), fuel relay switch and crank sensor.Check engine light is on now and showed the error code for the pick-up coil and crank sensor so that is why we replaced them. Also replaced battery as the last time it stalled there was a horrible rotten egg smell and battery was cooked.  Thought we had the problem cured but stalled when I was driving today. Sometimes can hear fuel pump hum when turn on key and sometimes not this Doesn't seem to make a difference whether Tahoe will start or not. Seems to hesitate mostly when slowly accelerating or the fuel system has a load(example going up hills, etc.)when it stalled the last time we fiddled with wires in front of rear wheel that connect to fuel pump and it started, yet when you have vehicle running and move those wires around-does not stall or even quiver!Mechanic has sprayed engine  to check for plug misfires & shorts. Engine did not stall.Last time after stalling and we got it started took it for a run with fuel pressure gauge attached. Fuel pressure did not budge when hesitating and "bucking"On occasion when starting, starter will just hum. Must turn key off and try to restart. Starter usually engages and vehicle starts. Can this problem be related? If it is something electrical  and not fuel related wouldn't the vehicle still run once the motor is running? This is driving me insane. Any suggestions?

Answer
Hi Denise,
Sounds like you are doing a great job trying to isolate the problem.
A dirty or loose wire connection could possibly cause both. Make sure the ground wire from the intake manifold to the firewall is intact, and tight.

The egr valve sticking open on some carbon is a possibility also.

Van