Pressure Chamber, has no pressure?

[JiM B]

I have a 1995 FD, with a completely standard set up.

I was having a second turbo-boosting problem, the car would pull very well from low revs but would appear to have no additional pull from 4000 rpm upwards. So the first thing to check was the vacuum / pressure system.

Released a hose from the pressure chamber (located directly under the strut brace and immediately in front of the plenum) to see if there was any pressure build up but appeared to be no pressure. Looked around at the vacuum hoses to fine a couple had come loose, replaced these hoses and went for another drive. This fixed the problem, the car is now performing as expected and the second turbo was clearly coming in at around 4500 rpm.

Once back released a pipe from the pressure tank again expecting a small whoosh of air to be expelled, but again nothing. I have check the ‘check valve’ and this appears to still be only allowing air to flow one way. Admittedly I checked the one way valve by removing it and attempting to blow through the valve in both directions, is this a good enough test?

Have checked the same pressure chamber on another FD and after releasing a hose the pressure was released from the chamber.

Does anyone have any ideas where my pressure is going?

Thanks,
James.

[jonrx7uk]

I have no pressure released from my chamber when i pull a hose off, and my sequential system works perfect...

Blowing through the check valve is a good enough check to see if its okay.

Cheers
jon

[nikp]

When i had twin turbo system, i got a release of pressure from the pressure tank.

[JiM B]

Thanks guys for that.

Can anyone else tell me if they have a pressure release from this chamber, it\'s 50 / 50 so far so still not sure if further investigation is required !