I got the JWT Flywheel and clutch from Mike@CZP for my 06 G35 RevUp.
i got it installed from the auto shop in vegas, first they installed it and my car wont start cuz they installed it wrong but they take it off and installed again for the 2nd time, my car runing ok but check ENG light is on "P0335", so i take it back to them to reinstalled it again cuz it can be the flywheel in the wrong position again but i am sure the 3rd time they install the flywheel position right but ENG light still on and they told me the sensor still good.

 

I dont know how they would have bolted the flywheel incorrectly....
You just bolt it up there and its good.
P0335 is a code for the crankshaft positioning sensor circuit malfunction.

 

I just had a JWT clutch and flywheel installed two days ago by Adrenaline Motorsports in St. Peters, MO. Mine is perfect.
These guys do a lot of performance Z work. Maybe check them out on the web and call them. Talk to Susan or Chuck. They might not be in your area but they know their stuff.
Check out Susan's Skyline while you're there.

www.adrenalinexxx.com

 

The timing ring might have been bent or chipped during the installation which will cause similar issues to what you are experienciung.

 

i have the same problem going on right now, my car is running in a safe mode, it sucks, we've done a number of things and still cant get it, we're gonna try check to see if the flywheel might be off by a couple degrees which would cause the timing problem. I even had JWT send me a new timing ring, which we installed, still the light persists, ***** really pissing me off

 

the hole with the key in it is the one that the dowl pin off the crank is supposed to go into... Ive installed over 20 JWT flywheel and never had a problem other than customer education on "noise" from tranny caused by solid flywheel... it has to be installed incorrectly or your cams are timed incorrectly if a buildup was done at the same time