Prob not the same thing but mine acted very similar when i built it from 1000-1500 and was a pain in the but to take off from stationary.
turned out i had the intake cam 1 tooth advanced and when VCT engaged it would hunt like yours and have no power. Disconnecting VCT or adjusting the TPS down a bit so VCT came in at a higher RPM kept it under control until i could pull it apart and adjust cam timing