Engine hangs at high rpm
Hey guys, I have had a problem with my E28 for a while now. It's a 1987 535is. I have replaced the distributor cap and rotor, the spark plugs, the air filter, fuel filter and a few other things. The problem I'm having is terrible gas mileage and not as much power as my engine should be making. If I rev the engine slowly all the way to redline, the engine hangs up at about 5000 RPM and starts making a tapping or snapping sound, I can't tell. It either sounds like an electric arc, or some kind of tapping. It is RPM related, so it's really fast. I adjusted the valves about 2k miles ago and got no difference. Disconnected the O2 sensor, no difference. Fuel injector cleaner, no difference.
The coolant temp sensor tested okay. I have also adjusted the wiper track on the air flow meter. None of this has helped my high rpm hang up.
I also did not buy new wires when i changed out the rotor and dist cap, so spark is not completely eliminated yet. $110 for those things! One last thing... I don't know if it's supposed to do this, or maybe it's just a characteristic of this car. When I'm driving, and I push the clutch in, the RPM's drop very quickly. I have to change the gears lightning quick to get a smooth shift. The car idles fine, and the RPM's drop fast but never go lower than idle and it never stalls. Maybe it's just me, maybe it's a related problem with what's wrong with my car. Feels like I've got a 2 ounce flywheel! Thanks for reading, any help would be great
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