Retarded boost when trying to map car?

[Jonas_R]

I have been having some weird problems at two different tuners when trying to map the boost. 1st tuner was a get and blamed it on slow gear change, so I aint using them anymore However 2nd tuner has been very helpsom, and God know we have tried many different things.

RS2 setup on the car with 3" turboback system, it is a 3b.

Boost works fine say in 3rd gear, it boost fine up to 1.7 bar with a 1 bar wastegate spring.
However if you run 3rd gear and then 4th afterwards then boost is stuck on mechanical boost at 1 bar to around 4500-5000 RPM and then it jumps up to 1.7 bar.
Something makes the car go away from WGFV control and it switch over to mechanical boost for a short while.

Currently the car is mapped with 1.5 bar spring since this seemed to cure the problem, however I would rather like to use the 1 bar spring and have some safety margin.

We have tried to switch ECU that did not help
WGFV is new
RS2 Maf is new
Vmap 3 bar mapsensor is new and working
Wastegate has just been refurbed and is in full working order.
All hoses etc. have been tested and they are airtight.

Anybody have any suggestions to what the hell can cause this or have experienced anything similar?

Currently converting to multi coil setup and AAN ECU and also installing a RS2 Evo wagner manifold, but not sure if that is going to help.

[S2central.net]

Couple of immediate suggestions here -

1 - Check the timing is perfect...

2 - Excessive knock (or a faulty sensor) can reduce boost or turn if off

3 - If the MFTS 'R' pin is active then it tells the ECU water temp is too high and boost gets turned off also - not on AAN strangely thoough

[Jonas_R]

1. How can I check the timing? Normally Audi changes the timing belt, so I would assume it is oki.

2. Will buy two new knock sensor and change them just to be sure

3. Oki so when changing to AAN ECU this feature will acutally go away then?

[S2central.net]

1 - Make sure the timing marks align and that with oscilloscope you can see every other crank reference pulse in the middle of the camshaft pulse

2 - Shouldn't hurt - except on the pocket

3 - Make sure you wire up the 'R' pin to AAN ECU. I think with RS2 software this safety mechanism will be restored. See the pinout info from last week. Pin 46 rings a bell.....

[Jonas_R]

Any idea in getting an RS2 WGFV or is that just a waste of money?

1. Where can I see this marks or is there info on s2central.net about it?

3. I will wire that in, however dont think it is the problem since the water is not to hot when mapping the car.

[S2central.net]

No need to waste money on RS2 WGFV unless the orientation of ABY/ADU hoses means you cant use the 3B WGFV - it has slightly different connector orientation.

1 - Search here for my sticky on timing belt renewal... The mark on flywheel is very hard to see !

2 - Yeah but thats the point - if the water is cold but the 'R' pin alarm is ON then the ECU is being told about a high temperature event - regardless of what it reads from the water temp sensor

[Jonas_R]

But then if I dont plug it in, then it wont turn of boost if water is to high or low, correct?

However this should also happen if I go from 3000 RPM - 6500 RPM in 3rd, but it does not. It only happens when going through the gears, say 3rd and then 4th gear.

[quattro20v]

Taken from SMJ autotecnik webpage:

Terminal 2/R also provides a ground signal from this same connection to the A/C control head unit which also will turn off the A/C if the engine temp. exceeds 247F.

If your engine is not overheating, and you suspect the sensor is malfunctioning, you should test this terminal 2/R connection (Blue wire with green stripe) to ensure that it is not grounded by the sensor, from faulty wiring, or from corrosion.

[Jonas_R]

I dont think the sensor is faulty But thanks for the info.

[Rocco]

I have been having some weird problems at two different tuners when trying to map the boost. 1st tuner was a get and blamed it on slow gear change, so I aint using them anymore However 2nd tuner has been very helpsom, and God know we have tried many different things.

RS2 setup on the car with 3" turboback system, it is a 3b.

Boost works fine say in 3rd gear, it boost fine up to 1.7 bar with a 1 bar wastegate spring.
However if you run 3rd gear and then 4th afterwards then boost is stuck on mechanical boost at 1 bar to around 4500-5000 RPM and then it jumps up to 1.7 bar.
Something makes the car go away from WGFV control and it switch over to mechanical boost for a short while.

Currently the car is mapped with 1.5 bar spring since this seemed to cure the problem, however I would rather like to use the 1 bar spring and have some safety margin.

We have tried to switch ECU that did not help
WGFV is new
RS2 Maf is new
Vmap 3 bar mapsensor is new and working
Wastegate has just been refurbed and is in full working order.
All hoses etc. have been tested and they are airtight.

Anybody have any suggestions to what the hell can cause this or have experienced anything similar?

Currently converting to multi coil setup and AAN ECU and also installing a RS2 Evo wagner manifold, but not sure if that is going to help.

Jonas i cant help you,but i have to say you that in the spanishforum dedicated to our S2 there is a man with the same problem as you .maybe in 90% yes.
aniway he,s car is stock and for example whem he run,begins fine bost at 0,9bar,but just later the bost down to 0,4bar ( wastegate control) and juts next later up to 0,8ar again¡¡ its extrange yes but... he said that changed the DV to e forge 007p new and n75 new and he has continue with the same problem...

you whem your bost down to 1bar its because your wastegate spring its not the stock true?? if you mount the stock wastgat spring surelly your bost goes down to 0,4bar and just later go up to 1,7bar????

good luck, and if i got more clues i will tell you here ,dont worry.


excuse me for my poor english