Noted surge and bucking

Hello,

It sounds like it could be misfiring. Can we run the codes to see what comes up? Here is a guide:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please run down this guide and report back.

Cheers, Ken

Ken. I stopped by an auto shop and a code reader will not get codes as the check engine light is not on. No codes to get. Thoughts?
Thanks

I would start with a good OEM part tune up and service the throttle bore as well. Here are two guides that will help you get started:
https://www.2carpros.com/articles/how-to-tune-up-a-car-engine

and

https://www.2carpros.com/articles/engine-hesitates

Please run down these guides and report back.

Cheers, Ken

Thanks Ken. Will take your advice. Let you know asap. Dodgeman58

Please do :)

Ken. I changed plugs and wires. Was not the solution. What do you think about the vehicle speed sensor casing the problem?

It would through a code if the sensor was causing problems. It sounds like the MAP or clogged fuel filter. If the MAP becomes weak it will give a false reading to the computer without setting a code. Here are the locations for both below with a guide to walk you through the filter change:

https://www.2carpros.com/articles/how-to-change-a-fuel-filter

Check out the diagrams (below). Please let us know what happens.

Thanks Ken. Will change both and let you know.

Please let us know what you find. We are interested to see what it is.

Ken. I changed the fuel filter and MAP sensor. Still the same. The problem is when going down hill the car is bucking, no load on the motor. What mechanism slows the car down when on cruise control going down hill? done does not increase. Does the transmission brake? That is what the symptom feels like. Thanks

Yes, the transmission does hold the engine to the car when decelerating. Have you serviced the transmission recently? If not here is a guide to help walk you through the steps:

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

Can you please shoot a quick video with your phone so we can see what it is doing? that would be great. You can upload it here with your response.