Startup Issues

so for the past few weeks a have problems starting up my car.
When i start the engine it stalls 2 with in seconds.after 5-6 times of trying to start the engine… it starts and works fine. No codes or what so ever. I have a big filling that it is a fuel pump, or fuel pump regulator.
Did anybody have similar issues in the past?

Do you have access to a vagcom to read codes and look at measuring value blocks?
The engine cranks fine but will stall right?
Does the car feel slow or sluggish when reving it out?
Do you hear any humming from the right rear of the bench rear seat?
Have you ever replaced your fuel filter? - If so how long ago?

Usually when a B7 or older car starts up and then stalls I usually think there is an immobilizer issue. But it would be good to rule out the crankshaft position sensor and any fuel issues.

If you feel confident enough then you can disconnect the fuel supply line and have someone crank the engine to see if the fuel pump squirts out some fuel. I use a gallon coolant bottle to catch the fuel from the line but a big water bottle would work too.

Thanks for reply Jimmy,

The engine cranks fine then stalls. sometimes it cranks and doesn’t start up (only happen once yesterday when i inserted a separate piece of pipe with pressure gauge)

The car does not feel slow or sluggish
there is no noise coming from the back
I did replace filter a few weeks ago and it did not change anything. (i usually change it at every 40k)
With regards to immobilizer, i don’t think it’s the one.because VCDS does not show any related codes.
Why i think its a fuel related issue, because faulty fuel pump will not trigger the CEL ( on any audi).
I did disconnect the fuel line today and cranked the engine, it squirts a lot of fuel, however the fuel pressure is very low when cranking. after a few attempts it finally started and was holding high pressure.
I don’t know if my fuel pump is about to die…? the odometer just went over 220k.

Do you know if faulty fuel pressure regulator would cause the above issue.? In fact it would spill i bit of fuel which did not happen. ???

Do a big check for vac leaks. This can cause the exact same thing. Alao check ur maf. If thats off or low samw thing will happen

All the vac lines were replaced few month ago, no leaks at the moment.

I put a new fuel pump in today…it was working fine for the half of a day and then stall again…
It might be the crank positioning sensor…not sure.

Yes but you might have an pcv leak or maybe an injector seal leak…