I'm having a loss of A/C under hard acceleration like merging on to an interstate. Air flow from the vents drops off considerably. I read a post by Aye Roll earlier today (I hope he reads this one) that I now can't find where he pointed to a vacuum check valve leak as the possible cause of this problem. Is this the valve on the firewall near the brake master cylinder made by Ate ( black and white in color maybe??)? Many thanks!

bruce

on my 89 w/16v engine, there is a small switch that when the throttle hits it, it kills the A/C compressor... you might check if you have that on yours...

Cliff Scott
89 DOHC740

Thanks guys!

bruce

well more than likely its the vaccum bellow in the heater box seen it and fix many of them it is on passenger side remove knee cover and look for the vacume bellow with 2 lines on it disconect them one by one and check to see iff they will hold vaccum using a peice of hose and your mouth. normally the one with the yellow line gives up.It is a pain to replace the correct way but you can mutalate the box but do it right all this only after checking the check valve like said before. the part normally runs about 80 usd. good luck and I will hope its just your check valve but not likely.

look on the top of the intake manifold, near the throttle body. There will be a small hose fron the manifold to the firewall, and the check valve is located in this line.
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'89 245 Sportwagon, VX cam,K&N, Bil's, IPD susp & exhaust