Yet another N52 -> E30 swap thread

[kristov]

Excellent list - thank you very much!

[LukeJ]

So I now have a running and driving car. Well I did. And I will again when the heater valve arrives....

Yes, It's true. I was able to somehow get the wiring correct and get the car started. I drove it around the block and it was much stronger than the M20 it replaced. But the idle was not good and after driving around and getting fully warmed up, it would try to die and then recover over and over while sitting at a stop light. The following day I decided to swap the two O2 connectors and just like that it was all 'fixed'. The idle is rock solid and it starts right up like a modern car should. I took it through emissions and it passed easily. 1st and 2nd gear go very quick and then you're doing 80. The headers have a very satisfying throaty growl on full throttle and especially after 4k rpm. On steady cruise it's nice and quiet like a car should be. My E30 is now a bit of a sleeper, which is exactly what I was hoping to build.

[LukeJ]

Special Thanks to Nando and Hoveringuy for obvious reasons. Their work and development of the 'tune' that's programmed into my DME made things 'easy'. Thank you as well to another Sophisticated Gentleman who provided tons of input in the development process of my swap project. I hope he is able to finish his project someday soon.

[hoveringuy]

This is beautiful work and sets the standard!

[LukeJ]

Thank you Steve!

Here's an 'incomplete' wiring list that I compiled, edited, and added to as I went through the process and learned more about what I was doing. As of right now, this is an accurate snapshot of exactly how my car is wired. I am hesitant to post this super valuable information since I had to 'figure it out' but mostly verify that it is correct. The experience I gained while verifying the wiring is something that I believe every engine 'swapper' should be 'forced' to understand. I removed all the wiring colors I used from this list to make it less confusing. BTW my car is an '88 325is so your C101 may be different. Good Luck!

C101

Pin New Connection

1 Charge Light Alt.D+ to ins.cluser No connection, yet

2 Sta. oil level Oil Level Sens. Sta. Pin 1 Crab Box harness

4 Temp gauge Coolant temp sender Crab Box harness

5 Oil pressure light X60007 pin13 Splice

6 Switched 12V Power on pin 23 IVM

7 Switched 12V Power on pin13 EKP

8 Fuel rate input X60007 pin 1 Splice for Convertor

9 Engine speed X60001 Pin 21 DME

10 Dyn.Oil level Oil Level Sens.Dyn Pin 2 Crab Box harness

11 Svc.light reset Diag.Conn. (Service reset) To glove box

12 Check engine Check engine light To glove box

14 Speed signal X60001 Pin 17 DME

15 Unloader Relay LM Jumper to pin 18 C101

16 Diag.Connector ????? To glove box

18 Start X60191 Pin 1 IVM

20 Ground Coolant Temp/Oil Level Send. Crab Box harness
***** DOUBLE CHECK PIN 20 IS GROUND. EARLY E30s ARE DIFFERENT****

Circular Contact .05mm-1.5mm 61131376191 (x20)
1.0mm-2.5mm 61131376193 (x5)
2.5mm-4.0mm 61131376195 (x2)

Crimper SN-48B


EKP Connector:

1 Power 15A inline fuse ->
2 Ground
8 CAN_COM Spliced with pin15
9 D-CAN High
12 K-Bus Leave unconnected
13 Ign.switched power C101 pin 7
15 CAN_COM Spliced with pin 8
16 D-CAN Low

2 Ground Fuel Pump
4 Power Fuel Pump

Small Contact #59637151 (Mouser)
Large Contact #61138364834

Acc.Pedal: #35426853176 Connector:

1 Ground X60001 pin 10
2 Ground X60001 pin 23
3 5V Power X60001 pin 24
4 Output X60001 pin 20
5 5V Power X60001 pin 11
6 Output X60001 pin 7


Brake Light Switch pin 1 GRN/RED
pin 2 VIO/GRN


Back Up Lights GRN/WS
BLU/WS

OBD Pin Out

1 12v+ C101 pin 6
4 Ground Chassis on shock tower
5 Ground Under dash
7 K-Line IVM pin 41
8 Not used
9 DME X60001 pin 21
16 12v+ 5A inline fuse

OBD-II Plug Connector #61138380698
OBD-II Connector Contact #61138366598


X60001 Grey 26-pin #12527521528

1 D Can Low to 3-way splice
6 Temp. Sensor pin 1
7 Acc. Pedal pedal pin 6
8 Electric Fan PWM fan signal
10 Acc. Pedal pedal pin 1
11 Acc. Pedal pedal pin 5
14 D Can High to 3-way splice
16 Brake light pin 2
17 Speed Signal C101 pin 14
18 Clutch switch CruiseC connector pin????
19 Temp. Sensor pin 2
20 Acc. Pedal pedal pin 4
21 Engine Speed C101 pin 9, OBD pin 9
23 Acc. Pedal pedal pin 2
24 Acc. Pedal pedal pin 3

X60191 Black/Grey 26 pin x2 #8364862

1 Start Signal C101 pin18
2 10A power out OBD pin 16, Cruise control pin 4
4 Power Input 60A fuse tandem w/pin5 Red 14ga
5 Power Input 60A fuse tandem wpin4 Red 14ga
9 A/C On Power ?????????????
11 DCan Low to 3-way splice
13 DCan High to 3-way splice
14 Sport button out X60002 pin3 ???
20 Sport button in Sport button ???
23 Wake up signal C101 pin6
24 Back up lights Power to lights
34 A/C Pressure sw. A/C Dryer pressure switch
36 Back up lights Power in from chassis
39 Cruise Control X72 pin2
41 OBD OBD connector pin7

X60192 6.0 gauge red wire

1 100A fused +input


Cruise Control switch: X72 #83772349

1 Ground
2 IVM pin 39
4 12v+


****NOTE**** The above wiring list is based on the E85 Z4 and uses the Integrated Supply module (IVM).

[LukeJ]

So as far as the wiring goes, 'everything works'. With the possible exception of the cruise control which I haven't had a chance to test. Also, the DME doesn't seem to know when the A/C is on. I wired it, but I'll have to take a look at what's going on there. Maybe I didn't plug it in. The compressor does come on when the snowflake is pressed. The fan controlled by the PWM unit seems to work as intended. The DME controls fan speeds. The Aux fan also works and comes on when things get too warm or when the snowflake is pressed. The temperature gauge works and the needle sits about 2/3 to the hot side on idle and 1/2 during cruise. It got up to 3/4 while I was testing the A/C at idle and that's when I discovered I routed the heater hoses incorrectly. Doh! Once I get the car moving again, I'll report back on the cruise control and DME a/c thing.

The oil pan sender is functional, but needs to sit lower in the oil. When I start the car the check light is off for the oil level, but once I get moving the light comes on. 6.5 quarts puts the level at 'full' on the dipstick. I placed the sender as low as it could go with about 1/8" clearance to the bottom of the pan. I may end up bypassing the sender to keep the light off and just rely on checking the oil manually.

[LukeJ]

The X60191 connector is sourced from a later model BMW stereo connector. In order to make it fit the IVM, you'll need to trim two of the tabs on the side of the connector. Here's some other pictures as well.

[LukeJ]

The last picture of the previous post shows the gas tank vent valve. It's from an E60 and there was already a connector and wire in the Z4 wiring harness. I just plumbed the output from the charcoal canister to the valve and then out of the valve through a one-way valve (BMW OEM) and it connects with the PCV at the throttle body. I used the Z4 throttle body. The one that goes on the 3 stage manifold. It didn't have a PCV port like the N54 throttle body does, so I had to machine a hole and make a part to fit. I did this because I bought a brand new Z4 throttle body on Ebay for $40 and it is an inch shorter than the N54 body. I didn't know it didn't have the PCV port until it arrived. By the way, the two throttle bodies are identical in every other meaningful way. As far as I can tell. ***NOTE EDIT*** I forgot to mention that the N54 throttle body had a different connector than the N52. If you use the Z4 engine harness and the N54 throttle body, you'll have to change the connector on the harness.

[LukeJ]

Sorry about the glare/fuzziness in some of the pictures.

[LukeJ]

[LukeJ]

Here's how I hung the heavy muffler from the frame rail. The heat shield blocks the view of an 8mm bolt threaded into the side of the frame rail on the outer side. The threaded hole was already there, I just designed my bracket to exploit it. So it bolts in three spots and seems to be solid. Those boss' welded to the sides of the bracket are tapped to accept shoulder bolts. The last picture was my view for a couple weeks while I built the exhaust system. I made a bridge and then used 1/4" mdf to space the cats away from the heat shield.

[Panici]

Great to see you got it running!

[LukeJ]

Great to see you got it running!

Thank you!! I'm very happy to be moving on to the drive and enjoyment phase of this project!

[Northern]

This is a phenomenal amount of detail for how few pages are in this thread

[LukeJ]

This is a phenomenal amount of detail for how few pages are in this thread

Thank you. As the project progressed and I needed to learn more about what I was doing, I usually found it here on R3V. Now that I've reached the finish line, I thought it would be good to put a lot of what I had searched for in one place. Happy to contribute to this forum.

Just got back from an epic trip to Glacier National Park with my wife and kids. Now, it's 115F outside and I have to install the new heater valve and get things buttoned up so I can get the A/C properly charged. Stay tuned....