MadGrip

I'm hoping its nothing major and the fault can be found easily..

Tonight on my way home i hit 100 and glanced over at the boost gauge because something didnt feel right and the gauge was dancing around all over the place..

I stayed on the motorway (private one of course) for an extra juction and dropped to 4th gear and floored it.. again the boost went up, peaked at 17 psi , dropped to 15 psi as it usually does, then started dancing around again between 10 psi and 17 psi.

the car is a MY01 WRX due for its 20k service . It has an ABC fuel cut defender and bleed valve, which i adjusted slightly as it was running peak boost at 19 psi which i thought was a little bit high.

Apart from that the idle is fine and it pulls very smooth on boost doing "Reasonable" speeds.

Any ideas ??

Phil


{edited to say , that the normal VTA sound from the DV dosnt sound like it usually does either






[Edited by MadGrip - 11/4/2003 10:28:46 PM]

john banks

Probably the fuel cut defender is not set correctly for the bleed valve opening used.

If you overdo the bleed and underdo the defend then you get spikes and if it gets a bit colder, oscillations.

If you underdo the bleed and overdo the defend then you get no spikes, but boost varies highly with conditions and between gears - effectively open loop.

If these means nothing to you let the installer that put it in set it up again.

Also check for detonation.

MadGrip

Thanks for the quick reply John..

So could it be that by me turning down the boost via the bleed valve has upset something ??

And if so, if i revert back to the origional setting of 19 psi should it solve it ??

Also is 19 psi ok,to run the TD04 ???

sorry for all the Q's

Thanks in advance

Phil

john banks

Turning both down would be better. 19 PSI is a bit high on a standard ECU unless you have a knocklink IMHO.