Car stalls in neutral

[Phosoup253]

2005 legacy gt 5mt wagon 

Bone stock replacement ej255 engine 60k

Generic chinese vf40 replacement turbo and lightweight flywheel are only two parts that are not oem factory. 
Car stalls out very inconsistently and only when coasting in neutral. Doesn’t happen all the time, sometimes doesn’t even happen at all. I’ve found a solution when coming to a stop by just leaving it in gear and holding down clutch slowing to avoid potentially stalling out. I’ll be able to put in neutral after coming to complete stop without car stalling. 

Not sure if the the turbo with the stock tune playing a roll in dipping the idle down or lightweight flywheel causing any idling or dipping issues? Also, anybody else running stock t-50+ dual mass flywheels bolts on their single mass or light weight flywheel? Is this recommended. Thinking about pulling motor just to throw a single mass flywheel with correct bolts but seems like a lot a work if not necessary. 

Any insight regarding those two issues would be appreciated. 

Edited October 5, 2023 by Phosoup253

[KZJonny]

Totally fine re-using the T+50s on the new flywheel, most people just swap to normal hex heads when they put on a new flywheel becuase they're easier to use, and don't require the bit. Of course, you already have the bit to take them off don't you, so you can put them back on easily enough... 

 

Lightweight flywheel could be your problem with the stalling. Not enough mass to keep rotation when you come off the gas and clutch in at the same time.

On the other hand, it's strange that you can coast with the gear selector in a "gear" and your foot on the clutch but not in neutral.

 

Check the nuetral safety switch for proper function/ a fault? I am pretty sure there are specs for that in the FSM somewhere.

[relative4]

What are your fuel trims?  If you're super lean at idle, that could stall you out.

[Phosoup253]

Haven’t tried logging anything but I feel like it’s something fuel related also. 
Having a well known Subaru shop in my area take a look, they’re thinking it’s some type of vacuum leak base off my symptoms.  kinda gave up at this point I’d gladly pay $40 for a diagnosis from professionals.

 I’ll check back in once it’s figured out  
 

[relative4]

8 minutes ago, Phosoup253 said:

Haven’t tried logging anything but I feel like it’s something fuel related also. 
Having a well known Subaru shop in my area take a look, they’re thinking it’s some type of vacuum leak base off my symptoms.  kinda gave up at this point I’d gladly pay $40 for a diagnosis from professionals.

 I’ll check back in once it’s figured out  
 

You have a decent shop that does diagnosis for $40?

[Phosoup253]

$140** 

Pacific Import Auto Tacoma, Washington 

[relative4]

That makes more sense.  FWIW, you can get an OBDLink and BtSsm for less than that.  And a decent smoke machine for a similar price.  Independence!

[Phosoup253]

Considering it. Pulling this thing parts to throw a single mass flywheel and some preventative maintenance gaskets timing belts and whatnot. 
Let’s see if I come across anything peculiar along the way. 

[Phosoup253]

15 mins in then got pretty tired. (Lazy) Should have out by tomorrow morning if I can find the time.