Another thread with cold start problem. Please guys help!

[EmilS3]

It's been 2 hard hard years with spluttering, hard idling and pops and bangs in the morning. I've so many threads, changed many parts and still no result.
No fault codes in VCDS.
Parts changed:
-fuel pump
-fuel filter
-fuel pressure regulator
-spark plugs
-coils(red tops)
-crank sensor
-coolant temp sensor
-MAF sensor
-O2 sensor

 

[S3AMJ]

Have you checked for splits in vacuum pipes, etc?


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[EmilS3]

Oh yes I forgot. Every single hose is replaced and still...

 

[Retroman]

What viscosity engine oil do you use?

 

[killfame]

It's been 2 hard hard years with spluttering, hard idling and pops and bangs in the morning. I've so many threads, changed many parts and still no result.
No fault codes in VCDS.
Parts changed:
-fuel pump
-fuel filter
-fuel pressure regulator
-spark plugs
-coils(red tops)
-crank sensor
-coolant temp sensor
-MAF sensor
-O2 sensor

Same issue after base map was put ON on mine for The bigger injectors
Depends on the weather (hotter or colder) how rough the Cold start will be.
TB Tempeture sensor or bad Injectors , could possibly be? Had no idea. In your case You tried almost everything.
Usually I keep the throttle slightly , so it does not loose it self in spluttering and bangs and does not go Lean , as I am watching my AFR gauge
It takes from 30 to 40 seconds each time until It stays on it’s self as normally should do. Wierd. If I could possibly upload a Video So I can show you my case , if it’s the same one.
Ignoring the fact that the car wasn’t turn On for Two Months , same issue every Cold start .

 

[killfame]

What viscosity engine oil do you use?

I hardly doubt oil has anything to do with it.

 

[EmilS3]

Well fuel pressure regulator was replaced with brand new(3 bar).
Hooked up fuel pressure gauge and it showed only 1.5bar.
Bought brand new 4 bar fuel pressure regulator but the fuel pressure raised to 3 bar.
On the other hand the car now stars cold with no problem .
I'm still curious why with the 3 bar fpr holds 1.5bar and with the 4 bar for holds 3 bar?