Date: Mon, 13 May 2002 08:27:34 +0100
From: "Andrew Hookins" <>
Subject: Re: My dealer hasn't got a clue, can you help? ('97 9000 Aero, Manual)

Lee, Yes I was more or less repeating meme meme... Is the over-boost protection fuel cut-off mechanism active when the over-boosting occurs? If you're not getting fuel cut-off then this would suggest MAP sensor to me. If there is a leak in the hose to the MAP sensor that only opens under high boost then most of the time fuel metering will be correct, but would tend to lean out in this over-boost condition (BAD). If the MAP sensor is faulty who knows what is happening to the fuel metering. The MAP sensor _could_ be just be reporting a reduced pressure or may simply stick at some arbitrary level and not report higher pressures. In any event, I think that a problem here would allow over boost conditions without fuel cut-off. If there is a leak between the APC solenoid and wastegate actuator then fuel metering won't be affected. If the problem is here then you would get over-boost rapidly followed by very obvious fuel cut-off. AndyH "Lee Marshall" <> wrote in message > On Thu, 09 May 2002 13:42:37 GMT, (Lee > Marshall) wrote: > > >On Thu, 9 May 2002 09:27:41 -0400, "KeithG" <> > >wrote: > > > >>MAP - Manifold Absolute Pressure - on firewall RHS with a short silicone > >>vacuum hose running to the intake manifold. It has this vacuum hose and a > >>plug. It is about 1" x 2" or so. > >> > >>KeithG > >> > >Just checked the hose, looks in perfect condidition. > > > >I can confirm though they have not checked or replaced the hose or > >sensor as both of them have reasonable amounts or grime over them. > > > >If this sensor was faulty I presume the ECU would not know how much > >pressure the turbo was creating thus creating the overboost problem? > > > Also, if it was faulty would it cause other enigine running problems? > ie. the fuel mix. Apart from the overboost situation my 9000 is > running sweet.

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