OK I am at whits end with this tracker. Here is the scoop its a 95 2dr 16v 5 speed. It has recently started surging at highway speeds. I replaced the plugs, wires, cap, and rotor and it didn't help. It does not surge at idle, but it does not high idle when its cold either. I notice it most when im traveling down the freeway at 60 and start up an incline or hill. Then it starts surging like the motor is just shutting down for a split second and then coming back on.  If you floor it it goes away, it doesn't seem like its running a hundred percent but it does go away. It will also do it if your sitting in nuetral and try to hold the gas at a steady rpm. It will surge 3 - 4 hundred rpm. Please help before I sell this stupid thing ! Also there are no codes and the Check Engine light is not on.

but it does not high idle when its cold either.

Maybe start here, there is an adjustment screw(phillips) on the top/back(firewall side) of the throttle body, under a black rubber insert, It's on a 45 or so degree angle. Remove the rubber insert, and mark a set line with a sharpie. Then turn it 1/4 turn counter-clockwise. Your goal is to get no more than 1500rpm's when started cold, you may need to tweak it a little if 1/4 turn is too much. This could fix the surging too, but I don't know for sure.

when you say surge do you mean drop in power and if soooo is it only after you go into 5th gear.  I had something similar.  My timing was off  which in turn lead to low power outputs in highspeeds and a very low idle speed.  It was also very difficult for me to accelerate at a stop light.   Now I know that you don't have any codes but there might be a possibility that its not connected and or is not working.

  this is just an idea i dont have any solid proof :} you might also clean your EGR and PCV valves
 and check to see that your gas filter is clogged.  I hope that gives you some roads to take.