I have a 1989 626, and I am having a problem with blown vacuum/air chambers. It first happened 7 months ago and the chamber was replaced. It happened again a month later . The mechanics found that the mass air flow (MAF) sensor was not reading all the air coming across, and replaced that. It seemed ok until last week when the vacuum chamber blew again. The MAF appears to be ok this time. It appears that something is causing the system to push too much air through (I may be describing this wrong).

The first two times this happened was on the first attempt to start the car in the morning. This third time was when leaving work late in the evening. I don't think that I'm touching the gas pedal when I start the car, but I'm not 100% sure (if I'm thinking about it I don't touch the pedal, I just don't know whether I ever touch it without thinking).

Once the chamber blows, the car might start again but it won't run, because the plastic chamber has cracked open and there is no vacuum.

Has anybody else experienced this problem? Does anybody know what might be causing it?

I've found one posting on the internet that describes this problem. That person rebuilt the chamber with a pressure relief valve, but did not give details as far as what type of valve, etc. Does anybody have any suggestions on this?

I (and the repair shop) would appreciate any information anyone can offer. Thank you.