Possum Link wont hold constant revs

[Matthew Oliver]

Hi all Ive recently installed a possum link into my V1 WRX wagon, more or less standard car, grey injectors, TD04 turbo, and the exhaust consists 3" mid and rear sections with a standard downpipe. The car runs beautifully when under load, but if trying to hold constant revs (say travelling at 50kph along a flat road in 3rd, 4th or 5th) it will loose power momentarially and then get it back once the revs have dropped a bit... I can replicate this in my driveway by opening the throttle a little bit and try to hold the revs at 2000rpm ish... but it will just sit there and fluctuate between 1500 and 2000 constantly. I called link yesterday and they suggested increasing the fuel master, doing this smoothed out the problem a bit but made the car run extremely rich so wasnt really driveable. Any ideas or suggestions??? If you want more info ask away Matt

[Jurgen Biggelaar]

Hi Matt.

Unfortunately it's never an easy job to chase these little gremlins as there are so many variables.  I take it the car has never run quite right to date, is it something you shuold be taking back to your tuner to resolve?

Where I would start is servicing your TPS by attacking it with a can of contact cleaner and test it's output is consistant (really only if your tune is spanned across this).  Once done, don't forget to re-span it as per the manual.

Then I would look at reviewing all of your vacuum hosing stemming from the manifold to ensure there are no leaks (common problem that catches a lot of people).  Ultimately a smoke machine makes a definitively acurate and quick job out of this.

See how you go with these things and let us know how you get on.

Jurgen