Several years ago I had a valve job done, ... removed the head, timing chain,... the head was trued as part of this service. I did all repair work with my son, and it was a good learning experience. The car is running fine, but if I were to guess, it's low on power - but since that time I have been driving newer cars, with more power, so hard for me to compare. I recently checked my vacuum, AT IDLE, and at the manifold, it was 19in hg - not bad. When I connect up the vacuum line to the carb intake, the vacuum drops to about 7.5in hg. In reading about the vacuum on these 535i's, it reads..
Procedure:
1. Take your Bmw for a spin to warm up the engine. Turn the engine off and use a tee to tap a vacuum line. Connect the gauge to the tee.
2. Start the engine and take a close look of what the needle in the vacuum gauge will do.
3. The ideal reading would be a rock steady 17-22 in.Hg (inches of mercury) @ 1000Rpm. (I DID NOT CHECK MINE AT 1K RPM YET)

Possible readings:
- Low steady vacuum reading (15-20in.Hg) at idle:
This could indicate a problem with an external vacuum leak, late ignition or valve timing, low compression or stuck throttle.

I have checked all compression, 165 on each. So, I'm wondering:

- what would happen if I slipped 1 tooth on the timing chain when I disassembled the motor?
- Would the car still run?

- What if I connected a timing light up and looked at the timing marks at 600RPM? They should 'line up' I would think - I have not done this yet, but plan to this next weekend.

I may just have a compression leak? Will try to isolate this also.

Any other ideas, just to check out, could be appreciated.

Thanks

Scott