Car Vibrates...Rough Idle

[Chad989of2000]

Recap: Just put the engine back in after having to pull it to replace freeze plugs and put on a new tranny + clutch. Also replaced the intake mani gasket which works great, making good vacuum with no more leaking.

The car starts out by revving really high at 3k rpm and then drops sharply and stalls. After a few tries the car will eventually settle down but still surges slowly between 750 rpm and 1200 rpm. The car also vibrates very significantly. The steering wheel is also vibrating, not with the surge of the engine but constantly, enough so my keys make a constant ringing noise vibrating off one another. The car goes into gear and drives forward and backward just fine (amazingly in fact with the new clutch and transmission. The check engine light also came on, never seen it on in this car before.
I'm now beginning to suspect timing belt or balance shaft belt. Both were replaced, and I used the marks to line them up. But all the research I've done points me in that direction. The car vibrates at all rpm ranges. What could be causing the car to vibrate so badly?

 

[Chad989of2000]

Update:

Car drives fine...amazing actually, until you come to a stop sign and it goes into idle surge vibration mode. The car feels so good, pulls strong to redline and no surging/vibrating. Oh well, idle issues it is.

 

[Chad989of2000]

Still hear a "whooshing" air sound from TB area (different from "hissing") when idling and car likes to rev high then stall out on cold start up. Anyone venture to guess?

 

[Terry Posten]

Have you done a boost leak test?

I wonder if you have an issue with the FAIV. Maybe a blown rubber gasket.

What BOV are you using? Is it recirc or ATM?

 

[stealthtt24]

Boost leak test and how is your ecu?

 

[Chad989of2000]

Passed boost leak test fine after installing new intake mani gasket. I'm seeing good vacuum with the car. Plus with any leak wouldn't I see a drastic effect when driving the car? I had a small hole in my other Galant's intercooler piping and that thing wanted to fall on its face if getting on it. This one drives fine.
ECU has a Keydiver chip that reflects the car's current setup. All ECU caps have been redone thanks to Terry. I really don't see any issues in that department.

 

[Chad989of2000]

Also...BOV is a stock 1G (crushed)recirculating.