2001 lincoln town car sig, 65000 miles, it start stuttering at 40 mph on slight hills, seems to be getting worst, runns great at higher speeds on the highway. When idling is seems to miss ever once in a while. thanks in advance for your help.

suspension is off

Engine misfire maybe . Your best bet have a qualified technician check it out .

It sounds to me like a passing gear issue. Or even and Over Drive issue. Try this to find out. When you put the car in gear, instead of O/D, try regular drive. If you have a push button O/D then deactivate it. If you only have Drive, then try shifting into 3. Run the car up to the same speeds you were having problems with. If you don't have the issues with the higher RPM's then it is an Overdrive/Highway gear issue. If it still stutters, then it could be a fuel delivery issue. Good luck.

Sounds like low fuel pump pressure here ,put a gauge on and see what you get should read 55lbs

Ignition misfire , spark plug's , spark plug wire's !

Do you have a way to check the OBD codes for the car? Without the OBD code it is hard to pinpoint the problem. If it is a cylinder misfire, try changing the spark plugs in the car. If not, it is best to take the car in to at least have the codes read.

COULD BE FAULTY TPS SENSOR OR FUEL FILTER PARTIALLY CLOGGED.

Hi, my first recommendation would be to take the plugs out and visually inspect each one and check to make sure they are properly gapped, if they look fouled at all i would replace them without hesitation. try throwing a set of NGK plugs in the car to fix the misfires. other than that you may want to look at the wires. good luck joe

AUTO DASH SAYS 'REDUCED ENGINE POWER" TRANSMISSION FLUID SEEMS OK AND COOLANT OK. WHAT ELSE COULD IT BE?

I read this over and over on these vans, same problem, you will need to have the trans overhauled to correct this problem, a $3000 job on this particular car.