97 GMC suburban 6.5l surging woes

I’m driving a 97 GMC Suburban 4x4 with a 6.5l diesel at 168k miles. I have been having a problem with the vehicle surging and dying while being driven for the past 2-3 weeks. The motor will rev up in rpm’s as if I’m increasing throttle pressure, though I’m not, in cruise control or out. Initially I thought it was just a fuel supply problem, so the fuel filter and the fuel pump were replaced. Now it doesn’t die while being driven, but it is still surging whether idling, driving at highway speeds, or anywhere in between. Also, there is an infrequent clunk which I believe is coming from the transmission. The car even lurches sometimes when this happens. Does this sound like the same issue or multiple things? I’ve been told it’s vacuum seals/leaks, computer problems, transmission failure, and air in the fuel. Does anyone have any experience with this vehicle? Any help would be appreciated. Thank you!!

You may have a broken or loose TPS (Throttle Position Sensor).

Hey, thanks. I hadn’t heard that one before, but that does seem to fit. I’ll have that checked out.

In 1997 at the Chevrolet dealer one heavy line tech was kept very busy replacing injection pumps (and other components) on the 6.5, bag of worms in my opinion.

Give the factory flow chart and TSB’s for your concern a look over,something has bound to be there.

Well, it’s been pretty reliable for me for the time that I’ve owned it. The trouble shooting recommended a few things, which is why I posted here hoping to gain a bit of experiencial insight. Thanks

Did you stop at a paticular point in the flow chart process?