VX Ecotec AUTO Revving up/down or changing between gears @ 50-70 ks

[admk69]

My Vx Commodore auto ecotec V6 surges when on gas or petrol. It happens around 50-70ks. i can see the rev needle going up and down. I'm not sure if it's changing between gears or just revving. it has a pulling feel as it tries to settle at a consistent speed. I have cleaned the throttle body butterfly etc. did make things run a bit better but the problem still exists. I wonder if it's the gears? it's done over 300k and was recently serviced. Don't think it's the injectors as it still happen when on gas. no error codes came up at the auto-ecetricians

 

[som]

may not be the answer but some time ago my auto was behaving in a similar way and both my mechanic and an auto trans specialist suggested i needed a reco box.on this site someone suggested checking my plugs,leads and coils.i didn't know how to do that but in the end ,despite the fact that the plugs and leads were less than 30,000ks old i decided to try it as a lower cost option.i used all genuine parts. that was more than 50,000ks and a trip to darwin ago and the trans is running perfectly.my trusty vt has done almost 360,000 ks,perhaps someone can tell you how to test your plugs,leads and coils