Help from a genius please?!

[Sprakie2008]

Hey guys, I could really do with someones help! I'm lost!

Basically, some of you may know i have a supercharged golf GTI mk3, 8v... On idle it is hunting like hell! with popping and uneven sound coming from the exhaust. Then under load it coughs and splutters, and just sits at around 4k revs (pinking). I assume this is starvation of fuel seeing as though the spark plugs are showing signs of getting very hot!

Things I have tried to get rid of the issue:

Airflow Meter x3 - including re-wiring and repositioning!
Ignition coil
Dizzy + Rotor arm
Plugs
Gapping the plugs
leads
Fuel pump (3+4 Bar)
Air Temp Sensor
Coolant temp senser
Knock sensor
Timing
New fuel pump
Relays
Lambda

Thats all I can think of right now, no doubt you will have made suggestions I have already tried.. But any suggestion is helpful!!!

Also, I get the Sporadic Short - Upper Stop Value (Lambda) on the Vagcom; but its the hand held one, not the computer software so i cant post a screenshot!

Hope to get some help from you guys! Cheers

[GOLF-MK3-GTI]

What engine code?

[Sprakie2008]

Engine code is AGG, Sorry should have put that!

[Screech16v]

While I was reading this air leak sprung to mind,ie hunting and weak mixture

btw im not a genius lol

[GOLF-MK3-GTI]

Does it cut out at all?

[Sprakie2008]

I thought air leak at first, but can't seem to find one!
And nope, never cuts out!

[Screech16v]

I don't see fuel filter on your list?

[Sprakie2008]

Furl filter has been changed, one of the first places I checked!

[gazareth]

hi have you checked your fuel pressure?

[Screech16v]

◆ If the fault "Lambda control upper stop value" is recorded, this means that the lambda control has reached the "mixture enrichment" regulating limit. However, the lambda probe is still detecting a "lean" mixture.

Lambda control
 
 Upper limit value
 
- Short to earth
 
- No Lambda control
 
- Check Lambda control

 
- Injector defective (blocked)
 
- Engine running problems
 
- Check injectors for correct flow
 

 - Fuel pressure regulator defective
 
 
- Check fuel pressure regulator
 

  - Fuel pump defective
 
 
- Check fuel pump
 
- Unmetered air after air mass meter
 
 
- Check intake air system for leaks (unmetered air)