2000 Century intermittant problems

[jwichman]

2000 Century with 175K highway miles started having 2 intermittent problems and a gas tank issue.

Problem 1. While running up a long steep hill on my commute to work, there is a severe loss of power from the engine. The engine does not die, however the more I step on the accelerator the less power and more of a shuddering/bucking effect I get. It reminds me a lot of the hesitations common in the carbureted vehicles of the 70's and early 80's except power never returns as I press additionally on the accelerator. I stop the car, shut off the engine and count to 20. Car restarts and drives fine the remainder of my commute. No SES light or code associated. As the outside temperature has recently dropped into the 30 and 40 degrees the problem has not reoccurred, however as soon as the temps climb back above 50 or so the problem reoccurs and typically at the same point on my commute to work.

Problem 2. With the falling outside air temps, I have started to get SES light and a P0446 Code Evap Emission Control System, Vent Circuit Malfunction. This code is set very shortly after warm up, I am guessing once the computer switches to closed loop. I reset the code and turn off the light and it is fine for several days.

To date, both problems 1 and 2 have not occurred simultaneously. Problem 1 usually occurs when the outside air temp climbs above 50 degrees, problem 2 seems to occur when the temp drops into the 40's.

Gas tank issue. I have recently noticed is when filling the gas tank. When I set the hold down for the gas pump handle it kicks off as if the gas tank is full. I have to manually hold the pump handle and fill the tank at the slowest rate in order to keep the pump from kicking off. Seems to be consistent at several different gas pumps.

Not sure if any of these problems are related or not. Any suggestions?

Thanks,