Car Stumbles at 60k

Hi,
Just wondering if anyone else has had this problem. I have an 89 Regal with a 2.8 litre V6. Lately when cruising at 58-65 Km/h with an engine RPM of about 1800 my car stumbles slightly. Now this is only when I have the gas pushed down slightly to keep the car to speed. If I let it off or increase the speed and cruise a little faster at lower RPM the car rides smoothly. It's as if the engine is stalling and then catching itself causing surging in the wheels. I haven't heard the engine stall out during these periods and it dosn't backfire or anything like that. Any thoughts!

Welcome to AF. I'd check the fuel pressure and replace the filter if not done lately. Ignition misfire can also cause this. A dirty egr valve can be a problem here also. Lots of issues that must be diagnosed in an orderly fashion

I agree with Max but I would also look at the torque convertor solenoid. It may not be releasing when you step on the gas and therefore is causing the engine to stumble slightly. It is also possible that the engine has a misfire that is causing the problem. So if the plugs and wires are getting old you may want to change them just as precaution.