Lurching 40 to 50 mph slight hill

[Boar-Ral]

I have a similar problem with my 2005 H2.* Around 40 mph, if I am trying to maintain my speed or very gradually accelerate, the engine surges, you can feel it, and you can see the RPM rise and fall slightly.* If I try accelerating a bit harder, the RPMs increase and the surging disappears.* I went to the dealership and they recommended fuel conditioner, a new air filter, and throttle body service, because it appeared dirty.* They threw fuel conditioner in, I put in a new air filter, but didn't have time to get the throttle body serviced, though I did buy cleaner so I will be trying that soon.* The problem still exists, so I hope that it is the throttle body.* If not, I'm out a couple hundred for their "diagnostic."* I just thought I'd mention it, since those are relatively easy fixes.* Not the same vehicle, of course, but the limited similarities might be enough that the same solution might work for both.