Help required (I have no turbo boost)

[MATI]

No turbo boost > 0.7b after changing the timing belt

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Hello to everybody

My name is Alexandros and I am the owner of an AUDI RS2 96 model.
I am writing to you because I have a problem with my RS2 after I have changed the timing belt .

The engine starts but the boost pressure does not getting higher than 0.6 Bar aprox.
I have checked the engine for the following:
1) Air leaks .(one by one item with detail)
2) The westgate by-pass valve (membrane is OK-by applying vacuum)
3) The blow off valve (operates smoothly -By applying vacuum pressure)
4) By pass solenoid valve (operates OK - Also checked its resistance and found OK)


After connecting the engine to my PC and reading the fault codes I found the same exactly code you have found few months ago to be present:

00515 - Camshaft Position (Hall) Sensor (G40)
Open or Short to B+ - Intermittent

After clearing the above fault The engine started OK but after reving the engine higher than 2800RPM aprox. the fault appeared again on screen of my PC.
After repeating the above the fault code changed slightly to:

00515 - Camshaft Position (Hall) Sensor (G40)
Open or Short to B+

i.e with out the word "intermittent"

Can anyone assist in eliminating the above problem ?
I have looked for a very similar problem on the S2Forum mentioned by "mastermind" but I can not reach him.

P.S During the installation of the new timing belt :
a) the No1 cylinder was at TDC
2) the marking on the flywheel and the opening of the housing was matching
3) but the two marks on the camshaft pulley and the mark on the cover was 1/2 a tooth mismatching.
How do you comment on that ? Was this the correct way of timing the engine?

Regards Alexandros

[S2central.net]

Sounds like CMP (Hall) sender failure - or fault in wiring between it and the ECU.

CMP failure detection by ECU means that it will disable electronic boost control => no WGFV modulation => boost is limited by mechanical failsafe pressure in the WG spring. Hence why you are seeing ~0.7bar !

Are you absolutely sure the CMP was undisturbed during the timing belt change - you did connect it back on OK ?

BTW - I've seen the weirdness of your PS (3) on another RS2 very recently. Other notable members of the forum (Doug & Mark) have also noted the timing marks look wrong on the cam cover on the S2. Just make sure you are looking at the marks on the FRONT of the cam pulley as there are multiple marks on the rear.

Paul

[MATI]

Sounds like CMP (Hall) sender failure - or fault in wiring between it and the ECU.

CMP failure detection by ECU means that it will disable electronic boost control => no WGFV modulation => boost is limited by mechanical failsafe pressure in the WG spring. Hence why you are seeing ~0.7bar !

Are you absolutely sure the CMP was undisturbed during the timing belt change - you did connect it back on OK ? IT IS CONNECTED BACK ON OK . HOW DO I CHECK IF IT IS WORKING CORRECTLY?
BTW - I've seen the weirdness of your PS (3) on another RS2 very recently. Other notable members of the forum (Doug & Mark) have also noted the timing marks look wrong on the cam cover on the S2. Just make sure you are looking at the marks on the FRONT of the cam pulley as there are multiple marks on the rear.I WILL CHECK

Paul

[S2central.net]

You need an oscilliscope to view the signal on pin 2 - you should see a steady pulse train with a frequency in keeping with engine speed. Remember the camshaft pulley rotates at half of crankshaft speed !

So 1200 crank-rpm gives you 600 camshaft-rpm or 10 revs per second...


Paul


Paul

[porkkis]

Are you 100% positive that the timing is right and not off by 1 tooth?

Check the timing from the cam pulley and the crank 0 mark from the clutch cover aperture, not the front damper!

[MATI]

I will check the timing from the cam pulley and the crank mark from the clutch cover aperture and I will let you know.

[MATI]

Hello
The problem was solved and the reason was the bad belt timing.
On the ADU engines once you set the flywheel mark correctly, the mark on the cam pulley does not match the V mark on the head cover. In my case was offset by half a tooth to the right of the V mark.By turning the cam pulley one tooth to the left the problem regarding the "hall sensor g40" was gone throughout the engine's RPM. Once the above fault is gone and the ECU "permits" the engine to produce the correct turbo boost.
Note that the cam pulley mark was still offset by half a tooth but this time to the left.
Regards
Alexandros

[RS2 Sedan]

its a old problem..at the rs2 the mark must be half tooth left of the cam cover..

[S2central.net]

That's consistent with what was found on AAH's RS2 recently. I didn't realise this was an old problem. Consistency is GOOD !


Paul

[mastermind]

Hi will try this on my RS2 and c if it works.

Rgds
mastermind

[AAH!]

My low boost problem was EXACTLEY as discribed in Mati's first post and was fixed in EXACTLEY the same way.

The difference is it took me six months to work it out!

Angus

[cochemaniax]

Hi,

be careful, the RS2 cam mark is always a half teeth different.
Never try to fix it like it is by the S2.
Those things happened in Germany before the people get informed.
a lot of damaged motors until the hobbytuners knew it.

so long, Heinz
following link is the godfather of RS2 tuningOGEA RACING

http://www.ppi-tuning.de/index_en.htm

and his RS2 website(you can aske in english):http://www.rs-zwei.com

[S2central.net]

Anybody know WHY the marks are wrong on the RS2 and not the S2 ?


Paul

[AAH!]

Is it anything to do with the smaller waterpump pulley on the RS2?

Angus

[4WheelDrifter]

Is it anything to do with the smaller waterpump pulley on the RS2?

Angus

I think he might have something there.