RS2 No boost after 30seconds of startup

[RS2ZuidAfrika]

OK so perhaps i worded this thread incorrectly:

http://www.s2forum.com/forum/showthread.php?t=60366

My RS2 had a boost cutout initially at about 4500rpm, but has developed into a situation where it is virtually normally aspirated all the time- except if i switch off the engine and fire her up again.

If i pull away immediately after startup, she boosts all the way through in first and second gear, very very strongly! but by third the cluster shows (!) symbol and beeps three times, after which there is no boost for as long as the car is on.

Please advise.

Avantus let me know if you had the same symptoms before you sorted your timing to "one tooth left".

Thanks chaps

[A80Avant]

if you have the( ! ) look for error codes. there should definitely be some

[simon20vq]

First thing first the cam marks do not aligen with the block if this is how yours is??

[RS2ZuidAfrika]

this was in june

[rynaqui]

The G40?

[RS2ZuidAfrika]

The G40?

i think so too. But to get to that sensor is going to be a job!
trying to look at all possibilities.

[prj]

Check your marks incl. cam timing and cam belt ASAP.
Possible it has slipped one tooth. You will get the hall sender code then as well.

If not, then replace G40.

[Avantus]

When I bought my car with incorrect timing it was fine until 3500rpm or so. Then it cutted hard.
And that was in all the gears.

As Prj says... check the timing immediatly with that fault code.

[UrS4boy]

G40 Cam Shaft Sensor Info including PNs and DIY

i think so too. But to get to that sensor is going to be a job! trying to look at all possibilities.

If, after you check the cam timing, you find that you still need the G40 replaced, you can follow this procedure (modified as necessary for the RS2):

Nate P's G40 replacement procedure

Which is a link in this G40 post:

http://forums.quattroworld.com/s4s6/msgs/22580.phtml

Which was accessed by clicking on the G40 label in this diagram (all the other labels are hot links as well):

http://members.shaw.ca/speedtek/UrS%20Engine%20Bay%20Device%20Map.html

Here is what you will see once you get stuck in:

[RS2ZuidAfrika]

UPDATE on RS2 boost cut (MAP?)

UPDATE

So we set the timing one tooth to the left and cleared all faults- the previous faults have not recurred but the car is still in limp mode.

Attached Diagnostic report:

[prj]

It is in limp mode because of MAP sensor error.
Fit MPXH6300A inside ECU as replacement, if the original is gone or if someone has fiddled around.

Looks like it's shorted to 5V, because that's the only way you are going to get that fault code.

[UrS4boy]

I am quite sure the problem has nothing to do with cam timing. The ((!)) symbol in the autocheck is a 1st Priority Brake and Hydraulic System warning. Under such conditions, the ECU must be reducing the engine power by limiting boost, i.e. not operating the N75 WGFV. The engine bay harness has two brake-related connections: 1) the Brake fluid level sensor on the brake master cylinder, by the reservoir, and 2) the Brake pressure sensor, two separate insulated spade connectors just below (1) on the front edge of the brake servo (shown for example in the AAN harness diagram below). My guess is one of your wires came off (or you really do have a brake servo pressure problem - or the sensor is borked)

Look on pages 2/16, 8/16 and 9/16 of this pdf:

http://www.leesehold.dsl.pipex.com/200/pdf/ffp2.pdf

Look in about the middle of this diagram for the two "24" connectors:

[prj]

The ((!)) symbol in the autocheck is a 1st Priority Brake and Hydraulic System warning. Under such conditions, the ECU must be reducing the engine power by limiting boost, i.e. not operating the N75 WGFV.

No. This will never affect the ECU. Limp mode is due to MAP sensor short to plus.
The only thing that does and shows up on autocheck is the MFTS switch.

[UrS4boy]

No. This will never affect the ECU. Limp mode is due to MAP sensor short to plus. The only thing that does and shows up on autocheck is the MFTS switch.

Please explain why the boost drop and the ((!)) symbol and warning beep show up at the same time.

[Vauhtiveikko]

Explaining that with out seeing the car is hard, but that could easily happend like so: Hard acceleration ->the Autocheck gives a (!) warning, let´s say about low brakefluid level and at the same time some other thing like airleak or wrong MAP reading cut´s the Boost. Has happened to me like this, just poor luck. It doesn´t even leave a code for the low fluid level... Mine was leaking from the clutch slave cylinder...