92 E36 325: no power under 3k rpm

[BC91]

Good Day
I have a 92 325 e36. A couple of years ago I noticed that, in the fall, the car would occasionally lose power when under 3000rpm.
The problem is now much worse. It starts fine always, but after it warms up you hit the gas and nothing happens. I can keep it idling by working the gas in neutral but in gear it wont go.
The BMW specialist in town had it for a week and couldn't solve this - they tried vacuum tests and all the likely fuel suspects. But they failed. I recently replaced the MAS and it still isn't fixed. That was my last hope.
Any ideas out there?

[Manolito]

A '92 has VANOS, correct?

I am guessing that the problem is that the VANOS is hanging up in the high RPM position. Sludge in oil passages? Leaking O-rings? Failing solenoid?

I know nothing because I have never had any VANOS problems. There may be an article in the 101 Projects book, or there is a place on the web called Beisan that specializes in repair kits for VANOS, their website looks informative.

[BC91]

My local mechanic figured this one out. Arc-ing ignition coil cause by cracked solenoid. He's a genius!

[Manolito]

I am sort of curious. Exactly what does it say on your invoice from the mechanic? There are several different solenoids under your hood, but none of them have anything to do with your ignition coils.

Ignition coils can indeed arc in a couple of different places, and cracks in the coil housing or spark plug boot can lead to arcing, but ignition coil problems generally manifest themselves at high RPM and load. This is because the higher the pressure in the cylinder, the tougher it is to ionize the air and fire the spark plug, so the spark finds an easier path to ground somewhere else. You described a problem that existed only at low RPM.