97 buick regal running problem

Hi Everyone Thanks in advance for your answers and opinions I have 97 buick regal about 131 thousand miles on it bought it about a month ago from a old woman never was driven often and car is in good shape. The problem I’m having is when I go to drive the car in the morning it will run at 2000 rpms at 55 mph than once the car starts getting warmer the rpms Will drop to 1500 1300 rpms and it will stick there you really have to press the pedal to get it to accelerate. Like something is holding it back car has a very very light miss at warm idle when I pull my foot off the gas it will buck hard sometimes it won’t buck at all. Replaced The plugs and Wires AC Delco plugs fuel Filter just did a oil change and air filter and Pcv valve replaced battery and alternator hosed down the intake with intake cleaner removed all the carbon build up cleaned the Maf sensor and still having the issue. Maybe Tps sensor?

@Lee Sanford

Any CEL (check engine light) illumination?
Have you checked for any DTCs (diagnostic trouble codes) that could be set and stored that would offer a clue?

For the engine to run at 2000 RPM @ 55 MPH while warming up then drop to 1500 RPM @ 55 MPH once it’s warmed up is normal. When it drops to 1500 RPM it’s because the lock-up torque converter is engaging. This is controlled by the PCM. The lock-up torque converter is disabled during warm up to aid in driveability.

“you really have to press the pedal to get it to accelerate.”

That is definitely not normal

@db4690 Yes, I’ll agree with you on that. My post was merely to explain to the OP the difference between the cold and warmed up RPMs.


And I agree with you about the stuff you said :grin:

To me, a high idle issue like that would point to an idle control motor not adjusted or not functioning. They aren’t expensive or hard to replace but there is a procedure for adjustment that needs to be followed.