Dodge Ram Hemi

What would cause my 2003 Dodge 1500 Hemi to act like I am tapping the gas pedal when I have the cruise on when going between 60 to 70 miles an hour. But works fine when using the cruise control at lesser speeds.

Normally a faulty throttle position sensor (TPS) will cause intermittent bursts of fuel from the injectors and cause an unstable idle because the PCM thinks the throttle is moving.

Now, this mentions an idle so I’m not positive the same will happen at a high steady speed.

We had the throttle body replaced, which I assume would include the throttle position sensor. Did not fix the problem. And the problem only happens when using the cruise control and going between 60 - 70 MPH.

What happens above 70 mph? If the problem worsens you may be suffering from weak fuel pressure.

So if you don’t use cruise, the truck runs steady at 65, 70, 75, 80? That should eliminate the fuel pump as a cause.

Yes the truck runs steady no matter what speed I am going, if I don’t use the cruise control.

I don’t think the problem worsens above 70, but I will check to be sure. If it was from weak fuel pressure, wouldn’t I have the problem whether I use the cruise control or not?

Get the truck scanned for codes. AutoZone will do this for you free.
Possible vacuum problem or a iffy speed sensor maybe.

Had it scanned, nothing abnormal showed up. But will check out the speed sensor idea.