Answer

If you could get a standard vacume gage and give me an idel reading at 1k and tell me what and how neddel moves, this will be easy... if not... keep reading, and go through these simple steps. before you get to ahead... pull on spark plug at a time, and write down what you see.. color, shape, and cylinder # it went to. then put them back. if you can make it run bad.. do this after a few mins or secs of that.
Remove distrubuter cap... tell me what you see. look for red powder, sometimes green, look for build up. Do ohms test on spark wires. write down tell me reading realitivr to what cylinder.
do this after the BIG hose tho..

If you are smelling fuel you have a fuel pressure problem. these use a mechanical fuel injection system that actually runs from the airbox. The air boxs has a diaghram that pumps the mechanical injection pump. once the fuel feed lines.. from injection to injectors, has enough pressure, the mechanical injector will fire fuel. The more throttle you give it the more air in sucks in, the more air it sucks in the faster the injection pump pumps, There is one thing you must check before we go any further... locate the throttle body. there will be a good sizr rubber tube from that to your air box. your injection pump will be mounted there also. This hose.. 3-6 inch diameter... eay to find; needs to be 100% sealed between the 2. other wire the car can suck air in bypassing the injection pump, this would cause a very uneven idle, sometimes car wont even stay running. this is also going to cause late injector timing, low pressure in fuel consequently slow or boging motor to stalling. If this hose looks good you may nee to remove the 3 scews/ bolts that bolt the top of injection pump down, you will need to remove 2 metal fuel line rails if i rember right to get all bolts. There is a tiny camshaft looking thing in there. unclip the aircleaner box, youll see a good size flap. push it down make sure cam moves. also check the seals of flap for build up. clean if present. there is also a little piston in the.. well most models.. depending on if the air box is right or left side of motor bay.
You will also want to check PCV. this is on a main intake vac line going directly from valve cover to the big hose. This is just a one way valve. pop it out and make sure it only flows one direction. motor should not be able to suck past it.. if it does replace, its cheep. However this does not relate to the loss of power while driving. jsut idel.
Another thing you will want to check is EGR is your model has this. exhaust gas recirulation... if this egr valve fails or sticks, it will be like a big vacume leak, causeing idle and power issues somtimes.
With this model your also going to want to check the fuel system electronics. Simply listen for a buzzing sound rear passenger side. shold always be there... common common on this model. You would be headed toward the fuse box and relays if this isnt as i say.

Check the big black hose FIRST for a solid tight seal between the airbox and motor, also need to check any lines that come off it and make sure they dont leak

Let me know, been awhile sence i have worked on this motor... this is all out of my head..

please responde with what you have done and results.
the injection pump has nothing to do with cold start. that line is always pressureized unless electronic "choke" is there. cold start.
lJacobTD40172.6308556713

Expert:	JacobTD
Pos. Feedback:	93.9 %
Accepts:	182
Answered:	12/25/2009

VW Mechanic

2 years Specialty Audi/VW training. With 2+Years At VW/Audi Repair Shop