hesitation under acceleration

[irvind]

Had some hesitation recently (just a couple of times) when giving it the boot, just a brief stutter. Not long after I'd put in a cheap tank of "I've never heard of it before" regular UL petrol. (It's all I could find at the time...) but it's been fine for a few weeks sine then.
My mech says he couldn't find anything, other than the fact that the fuel pump is putting out absolute bare minimum pressure.
After reading a few posts here, I see there's also a pressure regulator? Should I change one or both of these?

[urquattro-island]

it

could be the pump about to give in, mine did this and wham i was stuck in traffic, 8 00 ocklock during morning rush,... not funny.

my bet is the fuel pump.

[irvind]

Ok, thanks. I just wondered about the pressure regulator too, but to be fair, my mech didn't mention it, so maybe it's fine..

Edit: Having just spoken to him, the reason he didn't mention it is 'cos it's absolutely fine. I'll shut up now...

Over and out.

[irvind]

Ok, so a new fuel pump has been fitted, but the very infrequent hesitation is still there. Except it happened at the weekend in the outside lane when I wasn't accelerating... So in that respect it's a bit worse, but it hardly ever happens.
Any other ideas?

[Dpicariello]

Merlin's S4 had this happening on his S4 the other week (although it was mainly under boost). We swapped coil packs, ISV's and some other bits from my ar but it turned out to be the MAF.
Not sure if you've already tried this but either cleaning it with IPA (do a search for this) or if you have access to a spare MAF then swap it over.

Hope this is of help.

Dan

[irvind]

Excellent idea, will try that at some point, ta.

[Dan_s2_coupe]

U could check the MAF connector where it plugs onto the connector inside the unit a little pin on mine snapped and was just braking the circuit everyso often then was fine then it gave up completely