I just purchased 09 G37x sedan. Gent prior was doing head gaskets and gallery gaskets only to snap of cam threads on bank 1. I purchased and ordered a used head off of ebay. Swapped out heads and car won't start. Time was set by a pro but he's not familiar with these cars. My question is if it's in TDC and cams are right on bank 1 why no start? I have spark and gas in Cylinder 1...

 

Is your mechanic 100% everything is timed correctly? After all, you mentioned he is not familiar with these engines which, even for experienced mechanics, can be tricky to get everything aligned correctly.

Here is a link to a DIY thread about setting time on these engines. Perhaps @BULL , who wrote the DIY, might have additional insight.

 

I think between having a new vvel cam (used head replacement and left vvel assembly on head), needing ecu to re-learn new vvel and resetting vvel , may be the culprit to a no start.. im gonna reset vvel sensor and reset timing. Do an ecu reset, it should start... hoping and praying.

 

It's hard to say. I know that when removing/Installing the VVEL assembly that the position sensor needs to be calibrated (unsure if your mechanic new this)

One way to tell if he did the job right it to align the damper to TDC and remove the VTC covers and check the alignment of the cams. If all aligns then check VVEL position and adjust, lastly go over everything on this side as there are multiple grounds and sensors that could have been missed.

PS: after many failed starts the car should register a CEL light, see if you can obtain whatever codes it triggers as this can point you in the right direction.