M52B28 swapped,rough idle,sputter dies on first crank

[Bogdan66RIP]

Hello again
Im gonna try to make this short so please take your time,thanks.
I had a B20 which ran like crap, sputter rough idle things like this. I swapped in a B28 but i kept the wiring harness, ecu and all the accesories.
First thing the Crankshaft position sensor was bad, i changed it and the car was running like in heaven.
4 days later it beggan to run like crap at the first crank(slowly gain in rpms while starting, then when it reached 1000rpm it died)
The engine stalled when i engaged the clutch, but not all the times.

I beggan to check the engine very close, heres a list with the parts and things that i checked:
-Vacuum leak: Fuel pressure regulator hose had a crack in it so i changed it, all the other hoses are intact.

-Idle control valve: I had cleaned the icv, also i bought another one just to be sure but with no results.

-Injectors: I cleaned them and also watched them on a INPA diagnose to see if they run in parameters and its all good.

-Valve cover: all the gaskets are new.

-Oil filter housing: new gasket.

-Spark plugs: New.

-Coil packs: New boots and running good.

-Compression: 14bar(203psi) max 12bar(173psi) min.

-Oil feed line for vanos: New.

-Intake: new gasket.

-Throttle body: new gaskets.

-MAF rubber boot: new.

-MAF: cleaned and good.

-O2 sensors: good and running.

-Wiring harness: intact and good connectivity.

-Crankshaft position sensor: New and oem.

-Camshaft position sensor: New and oem.

The things i didnt checked yet:
-ECU
-Fuel pump

Im gonna leave here a link to a video with a cold crank:

https://drive.google.com/drive/folde...N2?usp=sharing


If you have any sugestions on which thing i should check next please reply, as i said i ve been fighting this problem for over a year now and i cant find the problem.
Sorry in advance for my long post i tried to make it simple and as short as possible.

UPDATE: The problem was CCV, membrane had a tear.

[samy01]

I swapped in a B28 but i kept the wiring harness and all the accesories.

Are you using B20 or B28 ECU?

[Bogdan66RIP]

B20 ecu with B28 software (ms41)
The guy who installed the b28 software told me that its the stock one.

[XnWarden]

"Compression: 14 max 12 min"

What are the units of this? Are you measuring in bar? It should be around 160-200 psi



Sent from my SM-G975U using Tapatalk

[Bogdan66RIP]

Sorry for not mentionig that, yes its in Bar.

[Eric93se]

I would just replace the fuel pump because they are not the same model.

[Bogdan66RIP]

I did a fuel pump swap but it runs the same