Author Topic: M42 swapped into my '85 325e (Read 3605 times)

Rogan · « **on:** August 24, 2008, 10:16:52 PM »

So I pulled the busted six out, and replaced it with an M42 from a '91 318iS..

The '85 had a 19pin square plug (C101), and the M42 has the round 20pin C101 plug. I cut off the square plug, and wired in the round pigtail. Here enlies the problem(s) There are 7 wires left over. I know one is SRS, which I'm not worried about.. But, the only two things that do not work in the car now, are the tach and the Engine Oil light is on in the Check Control panel..

I can't seem to find a good wiring diag that shows the tach wire and the Check Engine Oil wires for the car..

I have wired up the static and dynamic oil wires, so there's one left, somewhere. Anyone have really good wiring diagrams for the C101 for the '91 M42, and a good wiring diag for the Check Control panel for the '85 325?

Thanks!

vagrant_mugen · « **Reply #1 on:** September 05, 2008, 04:30:16 PM »

hopefully i will soon. ill keep you posted.

Rogan · « **Reply #2 on:** September 09, 2008, 07:51:05 AM »

So, the car is done, and has been for about 2 weeks. I have to say, that the M42/5spd, + the 325e rear diff makes it a bit n the gutless side, but 70mph @ 2300rpm.. 36-37mpg

The tach wire and econometer are now functional.. from the C101, the yellow/white wire, and the black wire, I jumped them to the small, white, 3-wire connector behind the glove box, so those now work. That leaves 5 wires

But about everything is now functional..

Rogan · « **Reply #3 on:** September 09, 2008, 07:52:47 AM »

Jimmy Lewis · « **Reply #4 on:** September 09, 2008, 10:21:05 AM »

I would venture to believe that a slightly lower than stock gearing a 318is would probably get better mileage than the 2.93 that comes stock in the e cars. I think tits1 swapped in a small case 3.64 out of an old m10 car and he gets very good mileage. Acceleration would also be improved drastically, not durastic in the sense that it will be fast but in the sense that it will actually accelerate, haha.

vagrant_mugen · « **Reply #5 on:** September 11, 2008, 11:04:01 PM »

Quote from: Rogan;56368

this is a most needed modification to the 80's-esque crome that bedazzles our e30's.

looks much better now :cool: but you still gotta paint the lock-rubber in the windshield seal

once i paint my car ill do this as well, but a running motor/car are definitly a priority.

i PM'ed you a couple Q's on the c101 plug, hope you dont mind....