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Vacuum Problem? 900

Here's a strange one. On my '94 940 (non-turbo), when I accelerate or when climbing an incline the air flow from the upper registers gets diverted to the floor and defrost registers. The airflow will return to the upper registers after accelerating. The fan speed doesn't change so I know air is being moved through the system. I assume this is a vacuum-related phenomena. I couldn't find anything in the FAQs that described this phenomena.


I have also had problems with cold starting for the last few winters. After cranking for some time on a near- or below-freezing day with the engine sputtering and dying, the car will finally start and run fine thereafter. I have found that holding the accelerator pedal all the way down while cranking helps. Also that manually opening the butterfly valve leading into the throttle body will also help. (I assume this is really the same thing.) I have read in the forums that cold start problems can be related to a vacuum problem so this problem and the airflow issue may be related.

Is there a good way to check for system vacuum, i.e. a good place to tap into the vacuum system to monitor the vacuum level? Also, what should be a typical vacuum level?

Thanks in advance,
Ron






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New Vacuum Problem? [900]
posted by  Imken  on Sat Feb 23 02:18 CST 2008 >


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