I have no overboost

[Graham]

I have installed a boost gauge on to the S2, and mounted it into the centre air vent. All the controls still work perfectly aswell . On tickover i get 0.5-0.6 bar vacume which seems ok. When i put my foot down i get when not fully up to temperature about 0.7-0.8 bar, once warm it occasionally hits 0.9 bar but i am not getting any over boost. I think my manifold isnt in the bestest condition, but all the studs are new so should come out if needed. I only fitted it 4 month ago. But other things i can see related are the WGFV and the WG diaphragm. The TBV is new and is all the hoses and the Mark H intercooler mod is donecould it be anything else????
Cheers
Graham

[Pisobiker]

Graham, if you get 0.7-0.8+ bar boost and your WG spring is stock, it seems to me your WGFV is actually modulating some boost. Just to make sure try to unplug it. This way boost shouldn't go over about 0.5-0.6 bar (or something less maybe).

Didn't you get any fault code?

Double check all hoses and bypass valve (BOV) making a pressure test. For the TB-ISV hose and the ISV-to-IM hoses I think you can only visually inspect them, better if taking them off. Check all of the thiny hoses as well.

Some tests you could do which cost zero-money and might give some results are:

- Multi function sensor: unplug it. Your in dash water gauge won't work, but if you have a dodgy MFS unplugging it will cure the problem (Tom's tip, AFAIK);
- Lambda probe: very unlikely to be the problem, but you can disconnect this one also (black wire, signal), and ECU will use default values for low throttle mixtures. Erase ECU memory before plugging Lambda back in.
- Test your Engine Temp sensor this way:

http://www.sjmautotechnik.com/trouble_shooting/20vcoolt.html

- Test your Air Temp Sensor this way:

http://www.sjmautotechnik.com/trouble_shooting/20vairt.html

You'll find infos also on all other sensors in the sjmautotechnik site.



Hope this helps.


Marco

[Graham]

Cheers Marco, i will try the freebee tests first, even though just now i got 1 bar coming home from work in 4th is the figure 0.5-0.6 bar for an aby as mine is an aby?. Also i have just changed the lambda probe to try and cure this problem to no effect, it runs a little better but not massively better.
Graham