Hi all!

I am new to this list since I have just acquired a '86 740 GLE (my SAAB c900 was totalled in a head-on collision). The car has Renix/Bendix ignition module, Pierburg 175 carb and 2.0L engine.
The thing is, that when applying throttle above cca. 2500 RPM the car looses power, but does not stall. Checking with a timing light I found out that almost always the ignition would retard from -10 or so to something like +20!!!
The engine stumbles and returns to normal advance after 20-30 seconds.
After disconnecting the connector on the ECU that go inside the cabin the problem went away.
I have read that somewhere that upon switching on the (electric) fan the ECU does something to ignition.

Any ideas from the experienced?

Knock sensor is a possibility. It's on the block below the intake manifold. Check for a good electrical connection and that it's mounted firmly to the block.

Erwin

Thanks for the effort, but this beast does not have knock sensor. The only sensor on the left side of the engine is temperature.
And one another thing - I have noticed that the car has b230 head bolted to b200 block. The casting on the head clearly states 1000530 which I reckon to be a 2.3L head.

If the head is a B230 then it should have a threaded hole for the knock-sensor on the intake-manifold side under. Next to it should be another for a gauge sensor, and a 3rd for the coolant temp. sensor (ECU).

Noel