98 civic hx cvt transmission problem surges when cold

[motomanred]

i just bought a 98 civic hx with 130000 miles on it. the car will surge pretty badly when accelerating for the first 5 minutes of driving, then it's fine for the rest of the trip. it doesn't matter if you warm up the motor or not so i think it's the tranny, not the motor. if you sotp and put it in park, it idles smoothly. if you rev it up, it's smooth, no pulsating, but when you drive it, it pulsates and you can really feel it surging. the tach shows the motor revving and slowing in about 1 second intervals. does this sound familiar to anyone? this transmission is only supposed to have 44000 miles on it because the original gave out. not for sure if the correct cvt fluid is in it, a garage did all the work, not a honda garage though. other than this, the car is flawless. thanks in advance for any help. motoman