Quick question; somebody I know needs to find out immediately whether or not the E28 and E30 engine wiring harnesses are the same if the engine is the same. The main question is: If an E28 has a blown B27 motor, will the wiring harness from that work with an engine from an E30 also with a B27 motor? The motors are not super-eta motors.
You might want to go search C.R.'s e28 forums, he's mentioned them here before, but I don't know the url offhand. I suspect they might be the same, they probably both use the 35 (? - well, not the later 55-pin) pin ecu. You'd need to compare the pinouts I imagine.
Absolutely not. The connections to the body are completely different. To boot, the harness for the E30 changes for the 86MY.
You will need to use the E28 harness ..however it is possible that some sensors or other electronics are not in the exact same places and some creative "wire stretching" maybe in order. Try to use as much of the old engine as possible ie: manifolds, thermostat housings, etc.
I mean use an E30 harness for an E30 and an E28 harness for an E28. This makes it plug and play. For super eta cars, you need an 88 harness for the approrpiate car. For 88 model year cars (super eta) if you want a super eta motor to work properly you need a super eta harness to match the car. If, for instance, you want to put an 88 325e engine into any E28 you need to find an 88 528e harness. No wire stretching is necessary if you use an E30 harness on an E28, but the plug to the body harness is different.