Help needed! not holding boost

[S2central.net]

At this poiunt I am thinking MAF or knock sensors.

[iib3327]

unplugged Altitude sensor got the fault code on vagcom also here's the readouts with it connected.

throttle opens all the way just double checked too..

[LHD_Kid]

Also worth checking the throttle adjustment, get an assistant to push the pedal to the floor and check the throttle is properly open under the bonnet....
Chris

[Jamo]

Altitude sensor? http://www.s2forum.com/forum/showthread.php?t=31676 and check this thread http://www.s2forum.com/forum/showthread.php?t=30290

[iib3327]

OK - so thats a stock ABY... Should be seeing 1.1 - 1.2 bar max on that with healthy factory setup.

Do the output tests on VAGCOM to make sure ECU can tickle the WGFV first of all.

Have you done a boost leak check yet ?

Tested the WG diaphragm ?

Tested bypass valve is airtight ?

Renewed the WGFV (old ones can be slow) ?

vag com clicks the n75 and on WOT u can feel it pulse

boost leak check 4 or 5 times

vacume tested the wastgate diaphram

bypass valve? (reserce maybe?) thats all air tight

has new n75 and tried 2 others (no change)

MFTS plug (water temp one under inlet?) unplugged this no change

[S2central.net]

Oh and try disconnecting the MFTS plug to see if that brings higher boost !

If all that is good, then you are into dodgy MAF maybe - or bad/loose knock sensors giving false positives.

[S2central.net]

OK - so thats a stock ABY... Should be seeing 1.1 - 1.2 bar max on that with healthy factory setup.

Do the output tests on VAGCOM to make sure ECU can tickle the WGFV first of all.

Have you done a boost leak check yet ?

Tested the WG diaphragm ?

Tested bypass valve is airtight ?

Renewed the WGFV (old ones can be slow) ?

[iib3327]

ecu software version from the "engine" module page

this one?



Jamo i'm running a alloy reserc i know is good, had a forge 007 on thier a cossie dump valve and a cheapo dump valve, thought these were all my problem so tried them all.

currently got my reserc backwards (same as my mates s2) as the chirp was getting on my nerves..lol

[S2central.net]

Didn't know it did it on ABY, cheers for the heads up

It absolutely does on ABY and ADU - the R pin is the chap.

[ericd]

output of what? only fault code i get is the normal engine speed sensor nothing else at all..

ecu software version from the "engine" module page

[Jamo]

What recirc valve have you fitted and which way round have you fitted it?

[iib3327]

any chance you can post up the current vag-com output ?

output of what? only fault code i get is the normal engine speed sensor nothing else at all..

[ericd]

any chance you can post up the current vag-com output ?

[iib3327]

well just stripped the wastgate again for no reason then

newsh i was getting that lurching when i fixed my boost leaks as the wastgate screw was wound right in (set to 0.4 with n75 unplugged now and stopped it lurching)

not thought about nock sensors yet.. i take it its just buy new ones to rule that out also?

cheers again guys..

[newsh]

If the wastegate diaphagm is split you will get too much boost, not too little. The air you here leaking inside the WG is just going down the WG valve guide into the exhaust, totally normal.

I'd be looking at the knock sensors if its holding back.

Or you still have a leak somewhere... ... normally though, if its a leak you'll get the "\MAF Cutout" effect and the car will lurch badly.

Bad knock sensors do not always throw up a code.