Boost Pressure Drops Then Picks Up

[pablo w]

hey guys, jst need some help. got a y reg impreza turbo 2000 uk seem to be havin trouble with boost pressure. when the car is on full boost it surges between [0.9 bar] and [0.4 bar] with out liftin ma foot off the throttle. I can only really feel it in 3,4, and 5th gears. Has any one had similar probs, any info would be much appreciated. thanks.

[the squiggle]

Boost solenoid on the inner wing drivers side

Remove it and take off both the air pipes but leave the connector connected. Under the dash next to the steering column there are 2 Green electrical connectors. Plug the Green plugs together. Now turn on the ignition but do not start. The boost solenoid will now start clicking away. Spray Brake Cleaner through the solenoid and you will hear the clicking getting sharper and noticably louder. Let the Brake Cleaner run through and dry out. Turn off ignition. Reconnect air pipes and refit solenoid to baulkhead. Reset ECU (How to can be found in SIDC FAQ). Boost should now be more stable in the higher gears

Hope this helps

[pablo w]

Boost solenoid on the inner wing drivers side

Remove it and take off both the air pipes but leave the connector connected. Under the dash next to the steering column there are 2 Green electrical connectors. Plug the Green plugs together. Now turn on the ignition but do not start. The boost solenoid will now start clicking away. Spray Brake Cleaner through the solenoid and you will hear the clicking getting sharper and noticably louder. Let the Brake Cleaner run through and dry out. Turn off ignition. Reconnect air pipes and refit solenoid to baulkhead. Reset ECU (How to can be found in SIDC FAQ). Boost should now be more stable in the higher gears

Hope this helps

thanks for ur help will try this tomorow

[ally-b]

Just a though , has it been serviced recently ?

This is a common problem just after a service/oil-change - if it has been slightly over-filled the excess oil gets through and contaminates the boost solenoid (which can be cleaned by following the procedure described by 'the Squiggle' , above)

Best keeping the oil level at the 'mid' mark on the dipstick rather than dead-on the 'full' line .

Al.

[pablo w]

Just a though , has it been serviced recently ?

This is a common problem just after a service/oil-change - if it has been slightly over-filled the excess oil gets through and contaminates the boost solenoid (which can be cleaned by following the procedure described by 'the Squiggle' , above)

Best keeping the oil level at the 'mid' mark on the dipstick rather than dead-on the 'full' line .

Al.

cheers al gonna give that ago 2day.

[pablo w]

cheers al gonna give that ago 2day.

cheers guys problem now fixed

keep boostin

[pmacFTO]

Bringing this topic back to life as I have just had a new oil pump fitted and obviously we had to fill up the oil etc and now my car is doing a similar thing to the symptoms described by the OP. It's a Newage tho so I was not sure how to clean the Boost Solenoid. It seems to go well enough in 1st and 2nd but is down on power in higher gears - sort of revs a bit more than normal and then boosts then drops off again.