92 2.5 M50 in my 89 E30(swap job done by some one before me); can't get a temp. gauge read; others told me to use the original one wire sender from the E30 in the M50 engine; but it's a different thread dia.. This engine has 3 senders/sensors in a row; front goes to the ECU, the next one is not hooked up at all, the next one is the single wire connector with brn/wt wire I have run to pin 4. While I'm at it, the goof who did this conversion had the IAT sensor run with it's own single wire to the pin 4 spot. I spotted a perfect fit 2 wire connector running off the Mass air flow wire bundle. I plugged it on the IAT sensor in the intake manifold. Does this sound like I got the proper connections going? I have studied wire diagrams till I'm ready to scream, nothing seems to "add up", Starting to wonder if this is some euro engine.
I just went through this on my '90 model this week. You need to transfer the temp sender over from the M20 engine (i think the part number ends in 512) and replace the M50's original temp sender with the M20 one. The M50's harness plug will snap right on and it works fine. IIRC the temp sender to replace is the "middle" one in the row of 3 you mentioned under the intake.
Thanks, I have now done that, but seem to have an addt'l wire or gauge problem. I'll get to the bottom of it eventually. The other thing that still baffles me that you may be of help is the Intake Air Temp.sensor (IAT); I recieved this engine without an intake manifold and purchased one used. In the bottom of this intake towards the rear of engine is a sensor plug; but other pictures I have seen show this on the side or very close to the main intake hole on the underside. I suppose it doesn't matter that much just where it is. The only loose connector I have on the harness that seems it should go to it is T'd off the wire/plug going to the mass air flow connector. It has 2 wires and one is red/wht as I recall, the other is maybe all red. It was such a pain to get my hand under there to plug it in that I don't want to take it off if I don't have to. Does this sound like the same IAT wiring that your car has. This one is from a 92 with OBD1.
Eesh, not sure without seeing pictures. Mine is also a '92 M50 but I pulled it from a car as a whole so everything just kind of stayed in their original places.
