I'm after some confirmation of what could be the problem on my s3 from anyone who may of experienced the same symptoms as what I am......
The car was fine up until yesterday afternoon, it had a long motorway run for a good couple of hours with no problems, stopped at a service station for 10 minutes or so then the car wouldn't start and run. It would start up but then struggle to idle and then eventually stool. If I gave it some gas on start up it would fire up and then start to splutter and almost misfire with the revs not increasing past 1200 rpm or so (even though I had my foot down on the accelerator) sometimes it would increase in revs but it wasn't happy about it and stuttered throughout the rev range. If I reached underneath the car and gave the fuel tank a good couple of whacks then it started up, idled, and revved perfectly fine. BUT, since this has all happened it now hesitating in spots throughout the rev range when on 3/4's to full throttle, light throttle seems to be fine throughout the revs but I'm not sure if a hesitating would be that noticeable on such light throttle.
Another possibility that crossed my mind was the crank sensor or coil packs, but both of those items were replaced on the car last year, the fuel pump relay was also replaced last year but I do know that it wasn't for a genuine audi relay. Those items were replaced by the previous owner when it wasn't starting at all.
The car is a pre-facelift s3 with pretty high mileage of 154k, its remapped to 260-270 bhp and is running a full milltek system from turbo back with decat and induction kit, but it's had these mods for years with no issues. If anyone has had the same symptoms and can help out I'd much appreciate it before I go spending hundreds on a new fuel pump etc.
Also if it is the full pump does anyone know of any there are after Market uprated pumps available such as walbro etc? Also what are the costs of a new fuel pump and fuel pump relay or crank sensor?
Thanks in advance,