Trying to find a problem with my 85 635csi--the engine ocasionally misfires--feels like deep "burps". When start reving the burps are more frequent. Somewhere around 3000RPM it seems to stop, although I am not sure--maybe it is just too fast to feel it...

Here is what I did so far:
Valve adjustment (.014 cold), new spark plugs ( WR9LS, set to .032), all new vacuum hoses, new O2 sensor, cleaned ICV, replaced injectors' O-rings, air and fuel filters, cleaned all the grounds, fuse and relay connectors.
The pump and main relays are new.
The transfer pump works.
Checked and cleaned AFM. The carbon layer shows good and uniform resistance.
Checked all the ignition wires. The coil one shows 2.3K, and all the others are within 5.8K-6.1K. To rule out completely, I swaped a set from my 325es--no difference.


What else to check and what usually causes misfires?

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