E30 m20b20 to m20b25 HELP

[4DoorE30 11]

Hi guys, I have pulled my m20b20 from my PFL l-jetronic E30.

-I have a m20b25 from a PFL 325i (no loom)

-I have the ECU from the same car (073)

I am currently under the assumption that a 073 ECU is motronic 1.0, Although this seems to be debatable. My ECU has only 2 rows of pins not 3 like you find on motronic 1.1 and 1.3.

The easiest option seems to be buying a motronic 1.0 loom, however I am unsure if my gearbox has somewhere to mount the two sensors in the bell housing. Does anyone know wether the l-jetronic cars have the mounting holes for these sensors, or a picture of what they look like?

If my gearbox doesnt have provisions for these sensors, and if my flywheel doesnt have the required tab. Is motronic 1.3 an easy upgrade?

Any input is much apreciated.

[will 169]

Your gearbox is most unlikely to have the mounting points for the cylinder ID and speed sensors, nor will your flywheel have the trigger tab.

At his stage, go for 1.3 motronic system as it is a far superior electronic system to the old 1.0 motronic. It is an easy install. The main bits you will need are a loom, crank pulley, crank sensor and ECU. You can source all the bits (including ECU) from a 2.0L motronic 1.3 and re-chip the ECU if you cant source a 2.5 donor (ECU's are the same apart from the chip).

You will need to carefully check your C101 (round) plug pin configuration, in particular pin#20, BEFORE connecting the new engine loom to the body loom. Failure to do so could result in a fire!!!! Reason is that early looms had a ground connection through pin#20, later looms often had a live feed servicing the ABS.

If you need any more info, PM me.