My 2.0 TFSI engine keeps stalling intermittently at any road speed/engine rev. During low speeds/revs the engine stalls, whilst at higher speeds it stalls and restarts itself. I've noticed it's slightly slower starting from cold too, but after filling up the petrol tank full (Shell V Power 99 RON) it still starts and stalls the same way. It's getting quite dangerous to drive as under acceleration I can sometimes slow down too quickly for the car behind. Just once the engine management light came on and stayed on. I stopped several times on my journey to restart the engine but the light stayed on. After 4 hours at my appointment though it started cold with the light staying off. Not come on since either. The engine runs smoothly with good boost, without any misfire otherwise. The engine has done 70,000 miles, full Audi service history inc recent cambelt, flush/oil/filters/plugs services. The coil packs were all changed under recall, plus the garage I bought it off had just fitted a new genuine HPFP (the sensor on top was broken). Not sure if the follower got changed too, nor the condition of the cam lobe. Standard engine (not yet remapped) other than new Forge turbo bypass valve and PCV breather catch can kit (which Forge fitted). In the past 2 weeks I've removed the intake pipe to the throttle body and cleaned it out with carb cleaner -which made a difference to the throttle but the stalling remains. Filling up the car today confirmed 24 mpg based on mileage.
Today I drove to Manchester and back on a family visit. It cut out several times -
Round a roundabout accelerating onto the M42. On all motorways it was then ok.
Going up steep hills on A & B roads it cut out loads of times. Downhill it was always fine. Then stalled turning at junctions.
I think maybe it could be the in tank fuel pump? The car runs perfectly otherwise.
If so, does any body know (including Olly - Olethalb with the K04 DTM ) if I fit the RS4 fuel pump like he has whether I need the RS4 tank controller as well?
I've booked the car in at Audi Coventry for Monday to have diagnostic check, but does anyone have any ideas in the meantime?
Many thanks in advance for your replies.