Vacuum leak from fresh air element?? IF you switch the the EC button does the center vent stay ON? if so then the fresh air vent IS the problem & is a very common failure.

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Ok I found that with the A/C on and the EC button depressed while driving...the air starts to blow out of the center vent more regular. With the EC button off the center vent will blow without the accelerator pedal depressed and will stop when you accelerate with the loss of engine vacuum!! I think I understand what you are saying but it seems to do the opposite because when you depress the EC button the vent starts to blow more regular and is not that dependent on engine vacuum!! Did I do the test correctly?

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