Hi

This is a very stupid question and I probably should'nt own an E30 BMW anymore after asking this, but how the hell do you tell whether you're car is a Motrnic of L-Jetronic System. My 1987 320i seems to have been made right at the time that BMW switched over to Motronic. One parts person at BMW says it is L-Jetronic and then another one says it is Motronic. My mechanic keeps changing his mind also. Is there a quick fire way to tell the difference?

Thanks

BeemaBoy

Motronic cars had the ignition timing mapped as well as the fuel injector settings. L-Jetronic only had the fuel settings mapped in the ECU.

Because of this, the distributors on Motronic are very different from L-Jetronic. Motronic Distributors don't have to vary the ignition timing and simply consist of a rotor arm and cap.

The Motronic rotor arm and dizzy cap are driven directly from the camshaft, and are situated at the very top front of the engine, right at the end of the camshaft-you'll see all the ignition leads going there.

The L-Jetronic dizzy has the ignition timing advance mechanisms built into it, and is situated on the passenger side of the engine block near the front, about half-way down.

The L-Jetronic dizzy cap is removed upwards, whereas the Motronic dizzy cap is removed forwards off the end of the top cam pulley timing cover, at the top front of the engine.

All E30 325i's were Motronic-early 320i's were L-Jetronic with a single exhaust pipe and 125bhp. Later Motronic 320i's had 2 small tailpipes coming out of the rear exhaust silencer box, and had 129bhp. I think 1988 may have been the change-point, unless someone out there knows better!

Hope this helps!

Alex