I Need Help!!!! Boost Probs

[quattrodude]

Hey all for some reason my aby s2 wont seem to boost over 0.4 bar

however when i disconnect the control valve and cap off both air box feed and waste gate feed and leave the turbo pipe free it will boost perfect but as soon as i connect back up im back to 0.4


iv dropped the batt off for 2 days to reset the ECU and still makes no diff.

so what ever is at fault aint to do with the ECU but seems to be puttin the ECU into limp mode.

any ideas as to what sensors could be causing the ECU to drop into limp mode????

or even how reliable the 3 way controler valves are??

any ideas would be great

Lukas

[slow2]

I would try another control valve (wgfv), is there another forum member close by
you, who you could swap valve with? I have a good spare if you cant find anybody near by, pm me your address and i'll post it over.

[S2central.net]

COuld be a duff WGFV alright... Could also be plumbed incorrectly...

Bottom hose should connect to turbo.
Hose nearest the electrical plug goes to WG and the remaining one is shoved into the MAF pipe.

Check there are no leaks in the WG or WGFV hoses

Check the WG diaphragm is airtight.

And oh check the fuse for WGFV is OK - seen that once or twice on cars that wouldn't boost past 0.4bar. Fuse 24 from memory - 3B or ABY...

[quattrodude]

cheers guys all have a play 2 day and let you know what i find.

[quattrodude]

Its been on the comp. and shown no faults so poss boost pressure sensor is faulty, the problem with that is its built into the ECU so theres no way i can afford to replace that so what about a aftermarket boost controller???????

any ideas or has any1 used them before and do they work good enough????

[Jamo]

Its been on the comp. and shown no faults so poss boost pressure sensor is faulty, the problem with that is its built into the ECU so theres no way i can afford to replace that so what about a aftermarket boost controller???????

any ideas or has any1 used them before and do they work good enough????

Eh? how do you work that one out?? Have you swapped ecu's with a working one?

[Jamo]

The other thing to check is cam timing, if the cam timing is incorrect the ECU won't allow any boost

[quattrodude]

no not swaped as i dont have another 1 and surly if the cam timming was out i would be able to tell by noise, power, etc...?
and plus it was boosting fine not so long back and i havent touched the belt and iv checked and tested for vac leaks and aint found any leaks.

[Jamo]

no not swaped as i dont have another 1 and surly if the cam timming was out i would be able to tell by noise, power, etc...?
and plus it was boosting fine not so long back and i havent touched the belt and iv checked and tested for vac leaks and aint found any leaks.

Nope, Only has to be out by a couple of teeth and that it

Search for boost problems by AAH.

I think your trying to quick fix the problem with the boost controller if you have a bit of spare cash take the car to MRC or anothe place of such ilk and have a proper diagnosis.

[newsh]

Check for a small leak in the line to the ecu or even inside the ecu, as there's a little rubber tube in there which can split, this will really mess up the way the ecu reads the boost and makes the car run strangely.

[Acidburn]

Nope, Only has to be out by a couple of teeth and that it

Search for boost problems by AAH.

I think your trying to quick fix the problem with the boost controller if you have a bit of spare cash take the car to MRC or anothe place of such ilk and have a proper diagnosis.

Mrc do a health check function which is probably one of the cheapest/easiest ways to find out whats up.

[quattrodude]

ok sounds good does any1 have any more info as to where this MRC place is?

Cheers

[Acidburn]

Unit 5,
Mead Park,
Thorpe Mead,
Thorpe Way Industrial Estate,
Banbury,

OX16 4RZ

http://www.mrctuning.com/contact.php