2.5TDI AKE limp mode

[kaptenboom@gmail.com]

Hello, I was hoping to ask some questions here, because tdi is not very happy, I have a 2000 audi d2a8 2.5tdi 180hp that i recently picked up.
Over the past 2 or so weeks, it at random intervals because loud, but just for about half a second and it would happen every few days maybe.
Which one morning seemingly ended up putting in to limp mode I presume, Its a ton louder than usual, it smokes a lot on idle. Sometimes while its in this state, it has barely any throttle response and wont let me go past around 1800rpm, it has a ton of powerloss in this state and will barely move.

Over the past few days, when started up, it will run perfectly normally for a while, sometimes longer, sometimes under a minute, before it will pick up a rough idle and go back in to limp mode, itll throw up the abs and esp lights and lose power.

So far ive tried changing the air and fuel filters and checking around some of the wiring, but cant seem to find anything too wrong. Tried to hook up an obd2 scanner, but it read no codes.

Which leads to today, starting up the car resulted in an extremely rough idle, which stalled it.
Eventually it would keep an idle and even run normally for about a minute, until again the abs and esp lights came on and it picked up a very rough idle (though not as rough as earlier when it stalled) and the smoking has picked up a bunch aswell, the color of the smoke is grey.
The throttle pedal basically gave no response either, the last time I tried to start it up, it idled perfectly normally for about half a minute, until entering limp mode, the idle became very rough, but even'd out slightly, I tried tapping the gas pedal, but all it would do is roughen up the idle or not respond at all.

I'm in a rough position where I have very little tools and no current ability to take the car in to have a mechanic see it, so was hoping to get some ideas for what the issue could be here. Thank you in advance.

[MikkiJayne]

You need VCDS as a priority. At the very least, pick up a '409.1' dongle off ebay or Amazon for £20 and then use VCDS lite. That will give you some usable codes from all the modules and we can go from there.

From your description I'm going to guess you either have air in the fuel system, or your 'start of injection' sensor on #2 is failing, but the AKE can have so many arcane faults that really is just a guess. It could also be sensors on the pump so proper codes are vital to make a sensible diagnosis.