325ix with strange engine behaviour

[apers123]

Hi Everyone,

I've just bought my first E30, a 1989 325ix Touring with the 'sport' Auto (which I plan to swap with a manual somewhere later on).
The car looks spotless and very well maintained, had a very recent cambelt change, new distributor cap, injectors cleaned, all new filters, valve clearances set, new waterpump. The engine does not smoke and autobox shifts as good as one can expect.

There do seem to be a few problems with it however...

First, the rev limiter seems to be set at 7000rpm in the autobox' normal mode , and no limiter whatsoever in sport mode.

Second, the engine doesn't seem to put out any significant power or torque below 6000rpm, but once it reaches 6000rpm, it becomes an absolute rocket.

The difference is so enormous, that the car is MUCH faster from 100 to 110 than it is between 60 and 70.

Third, it idles at about 1100 rpm, although it's a stable idle.

This makes me think that there might be a vacuum leak somewhere, which might also be causing the engine to run too lean?

However, I strongly doubt that it would be the only cause for this behaviour.

Could it be that the cam and/or ignition timing is off, or some sort of electric/electronic issue?

What would be a good place to start looking?

Any help would be greatly appreciated.

Best regards,
Axel

[Speedtouch]

Sounds like it may have been chipped - remove the ECU lid to find out; a standard BMW EPROM chip should have a silver label on with the part number, e.g. 1 267 356 372.