I had to change a broken VVTI controller for a Toyota Raum to my surprise the car won't start after checking the compression it read 90 psi on # 1&4 cly and 30 psi on #2&3. The reading before the job started was 160 psi on # 1&4 cly. and 150 on #2&3 cly. I just can't figure out what cause the significant drop in compression.

Sounds like either the valves aren't closing all the way or the chain jumped and timing is off. May need to verify where compression loss is going with a leak-down test-just be sure you've installed an oem vvti component, and if so, the front timing cover may have to come off to check chain timing or see if a vvt gear is stuck.