Date: Wed, 16 Sep 1998 13:31:57 GMT From: <jvanabranopsamnet> wrote: >Paul Aspinall wrote: >> >> I have an 89 9000 Carlsson. I have had problems with Turbo boost for a few >> months now. The car seems to imtermittently reduce itself to basic boost for >> no reason (ie. the boost guage moves half-way into the yellow). >> Occassionally I do get full boost (all the way into the yellow), but it is >> quite rare. >> >> I have changed plugs, air filter, cleaned injectors, tried new boost >> solenoid - but no luck. >> >> Has anyone had this problem, or can anyone help??? >> >> Thanks > > >Did you try a new APC box? That would be the next place to >look. Either than or a vacuum leak. > >The APC box is the *sole* controller for boost. It interacts >directly with the APC solenoid, so if you're getting basic >boost, it's 'cause the APC box said so - given that the >solenoid itself is good. > >Now, things that will normally cause basic boost are a >failed apc box, a failed knock sensor (may give the >*illusion* of basic boost) or the cruise control system >being engaged or malfunctioning (check the pop-off valve >near, the clutch & brake pressure switches, and the >cruise control 'ecu' itself). > >My money is on a bad APC box, though. > >-Justin