Chrysler Repair: code 172, engine runs rich, chrysler grand voyager, emissions systems

Question
I have a 2000 Chrysler Grand Voyager mini van with a 3.3L engine.  For several months I and my mechanic have been trying to diagnose why the engine light continues to come on with the code 172 engine runs rich.  We have replaced everything in the emissions systems (sensors, catalytic converter, CKP/CMP, evap, MAP, Idle control valve, etc) and fuel system parts with fuel pump and filter. Many times at idle, especially in neutral or in park, the engine surges up and down about 400 rpms. Vacuum pressure also pulses up and down with the rpms. Also after drivng at speeds over 30 mph, you come to a light or stop and the rpms drop to 400 - 500 and engine almost dies. I have spent over $1500 trying to fix it.  Even tried a new computer.  Nothing has worked. Also, The other time is when you are going 60 mph or so and try to accelerate, there is hesitation and sometimes the rpms move up a lot and seems like it is getting a lot of gas, but not kicking the transmission down to lower gear. So seems like tied to vacuum or timing. Any ideas?  Thanks


Answer
FUEL PUMP MODULE DEFECTIVE
TPS VOLTAGE CHANGE NOT SMOOTH
TPS VOLTAGE <0.92V
FUEL INLET STRAINER PLUGGED
ECT SENSOR DEFECTIVE (OUT OF CALIBRATION)
MAP SENSOR DEFECTIVE (OUT OF CALIBRATION)
ENGINE MECHANICAL PROBLEM
FUEL FILTER/PRESSURE REGULATOR DEFECTIVE (HIGH)
FUEL FILTER/PRESSURE REGULATOR DEFECTIVE (LOW