No Passing Power

2000 Century with 190K miles has no passing power. Engine runs fine up until about 60-70% throttle then no power. Noticed this the other day when attempting to pass another vehicle. Later while stopped and trans in park I slowly opened the accerator until the same loss of power occurred. No DTC are set, engine runs fine until reaching the 60-70% open throttle position. TPS sensor appears to read correctly. Problem seems to occurr consistently. Any thoughts?

If you've verified the TPS operating correctly, perhaps a plugged fuel filter.

If you've verified the TPS operating correctly, perhaps a plugged fuel filter.
Yes I believe the TPS to be working correctly and I replaced the fuel filter yesterday.

What was the TPS output reading at idle/WOT? Also, have you checked fuel pressure to see if it is in specs? With no DTCs or SES/CEL light you may have an ignition related problem on the high voltage end. ICM or coil packs. Another possible cause based on your symptoms could be a clogged CAT convertor.

I have a scan tool which allows me to view limited sensor data while driving. TPS at idle is .4% and 100% at WOT. Problem seems to only occur at cold startup (hesitation) when fuel system is in open mode or when fuel system switches to open1 acceleration mode. Everthing seems fine while in closed mode. I am planning on checking fuel pressure, can you provide me with pressure specs?

Fuel pressure will vary depending at what point it is checked. Fuel pump prime (ignition on), with vacuum at the fuel pressure regulator connected and disconnected at idle. I don't recall the specs for a 2000 Century with the 3100 V6 but it should be up in the 40-50 psi range. The Schader valve/port is located on the rear fuel injector rail by the alternator.