Could be your fuel pressure regulator (OE Part# 025133035), as the engine accelerates more fuel is sprayed into the cylinder by spraying for a longer period of time. The fuel injection pressure regulator is designed to maintain a set fuel pressure (between 25 and 60 lbs.) no matter if you are idling or accelerating.

If it isn't idling right, then a more costly fuel injection idle air control valve (OE Part# 025906457A), which modulates the air mixture entering your engine at idle. If you car has a rough idle or is unable to idle without use of the accelerator pedal, you should inspect this valve for any obstructions and clean or replace as necessary.

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Rick Cooper
Sent: Monday, June 15, 2015 10:25 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Engine hesitates upon take off

I've noticed that when accelerating from an intersection, after sitting at a red light, my 2.1 WBX will sometimes hesitate for 5 to 15 seconds.  I'll start moving, but the engine has no power and giving it more gas does nothing.  After those few seconds, the engine will start to pick up power and soon everything will be running fine.

This has just start happening and is still sporadic, but it is becoming more frequent.  Seems to only happen after a full stop, like at a red light.  Would this be a clogged fuel filter or what?

Thanks for any ideas.  FWIW,  the fuel tank and the ECU were replaced a few years ago.

Rick