Help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!????

[Albie S2]

Hi

I need help here,i have a 91 s2 3b and this thing is driving me crazy first thing is when i accelerate the boost gauge indicate 0.9 bar and as soon the car start performing well the boost drop to 0.5bar and then at 5000rpm it the boost is 0.9 bar again this happen in every gear.I started to pull the error codes and 1 is carbon canistor valve that is no more there and the other is lamda sensor,now lamda sensor wont limit the boost due to it will overfuel but if i bridge the carbon valve i here something in the front of the turbo clicking now when i accel i also here this clicking by the valve at the turbo can any1 help here.

thks.

[S2 Ant]

The clicking would be the WGFV i believe trying to control the boost.
I would think this is a leak and its trying to prevent the turbo being overspun.

Check your hoses I think

[Albie S2]

i have checked all the boost hoses no leaks at all.

[Honahon]

i have checked all the boost hoses no leaks at all.

how have you checked the hoses mate?

[porkkis]

Standard or chipped?

Replace the lambda.

Try unplugging the carbon canister valve. Get rid of that fault code.

Could be also the ambien pressure sensor. At what altitude did you test?

[Albie S2]

Ok replacing the lamda sensor is a bit difficult because i am from south africa and audi doesn"t have spares on the s2 and secondley there is no carbon canister valve anymore only the electrical plug and the pipe out of the back of the cyl head is blocked off,can i bridge the two point on the plug?

[Albie S2]

sorry its standard and the altitude is about 1200m above sea level.

[porkkis]

Get any 3 wire bosch lambda and replace the connectors from the old one. DO NOT SOLDER THE SIGNAL WIRE.

Dunno if you can short the canister wires. I would't try that. I presume it has nothing to do with your problem but these are mysterious vehicles...

[Albie S2]

Ok i will try to get a A4 lamda sensor and put it in see what will happen then.Does this mean that the lamda sensor can limit the boost at a certain rpm range.

[porkkis]

No but a faulty sensor messes up the mixture and might cause detonation and that's prevented by adjusting the boost and ignition timing, right?

[Doug_RS2]

Get any 3 wire bosch lambda and replace the connectors from the old one. DO NOT SOLDER THE SIGNAL WIRE.

Why?

[porkkis]

I guessed you want to know.

The answer is quite unbeliveable so I'll leave this explaining to someone who can do it in mother tongue. Hopefully someone knows.

[S2central.net]

huh

[kwlw]

Stupid idea - just try to pull control hose from wastegate with some moderate force (like 2-3kg). Sometimes this hose is leaking, however, clamp, and hose itself look ok.

I've seen this effect on unchipped 3b. When you accelerate hard, boost comes to 0.9 bar, and ecu cuts fuel or something. However it always said "overboost error" or something like that, so it may not be your case. But it still worth trying anyway

Sau

[Albie S2]

Ok but it does"nt give any error codes of overboosting!!!