legacycentral bbs

Hi,

I've got a factory 92 Gt legacy turbo. I recently found that the outlet for the tubro boost controller solenoid valve had been deliberately blocked up! I cleared it & now the car boost much harder (10psi instead of 5) BUT the power pulses baldly, especailly if you put your foot down! What may cause the power to fluctuate quite badly (while maintaining fairly high boost)? It tends to pulse less when you only put your foot halfway down. maybe the knock sensor? I've put in higher octane fuel (98 instead of 96) & it made no difference.
Thanks for your help.

Luke

It could be a knock sensor issue. Some Subarus have trouble with oversensitive sensors. I don't know about non-US models, but in the US they issued an updated knock sensor with a different part number and a differently-colored connector which is meant to alleviate the problem. You may want to ask a dealer about it.

You bought this car used? I would guess that the problem is not the knock sensor but rather a defective boost control solenoid. When they go bad sometimes they are unable to cycle quickly enough and the hesitation you're describing is a symptom. That may be why a previous owner blocked off the line. A cheap manual boost controller is probably the best way to fix it if this is the problem.

it will also fluctuate up and down if you are using a manual bleed valve in conjunction with the standard EBC.