Car Wont Boost

[Erni902]

Evening guys, so after fitting my FPR yesterday and driving steadily back I noticed I had a potential boost leak somewhere as the BOV was barely noticeable. Left the car overnight as was shattered. Took a look this evening and checked all the vacuum hoses I removed yesterday to get to the FPR they all checked out fine.

Removed the TB elbow and hard pipe etc and reseated and tightened up again. Now when I floor it I only get 8psi max. I have switchable maps but definitely have the correct 15psi map selected so this is a huge 7psi drop. What could be causing such a significant drop in boost? Has a turbo gone pop?

There is now issues when idling no hunting/fluctuation holds steady and is absolutely fine to drive without hesitation or cutting out etc just missing the extra 7psi (god this feels slow)

Any ideas?

EDIT: Oh and the vacuum pressure stays at a steady -9 whilst idling which is no different to normal.

[Erni902]

Okay suspected something to do with the boost solenoid, (due to huge loss of boost and no whistles/noises etc) checked all connections etc and all was good and sealed, checked the vacuum hose from the TB elbow to the solenoid (the red tipped one) I had swapped this over at the weekend for some silicon hose as it was looking worse for wear (no splits but has been on the car for nearly 20 years now)

Something told me to just check the original hose, when I picked it up I noticed it was hard near the red tip, after looking down it there seems to be some sort of valve or something inside the hose.

I replaced the original hose and went for a spin (just round base so only a 2nd gear pull as I didnt want to take the pi$$) and I noticed a difference straight away in the torque looked down and the boost gauge showed 11-12psi. Didnt have my pass and was only wearing slippers so didnt venture off base to test fully but will head out tomorrow and see if she makes full boost again.

[Nick Mann]

The restriction in the red tipped pipe prevents too much air flow for the solenoid to bleed off. If the solenoid is unable to bleed enough pressure then the actuators will open the wastegates. If you have an aftermarket solenoid then you can probably tune it with the replacement pipe, but the stock solenoid needs the restriction in the red tipped pipe.

[Erni902]

The restriction in the red tipped pipe prevents too much air flow for the solenoid to bleed off. If the solenoid is unable to bleed enough pressure then the actuators will open the wastegates. If you have an aftermarket solenoid then you can probably tune it with the replacement pipe, but the stock solenoid needs the restriction in the red tipped pipe.

Aha well yes that does make sense now thanks for the explanation Nick. She is indeed a stock solenoid not overly bothered about having a silicon hose on there Ill just get a brand new replacement form Mitsy.

Many thanks again for the input Nick every day is a school day.