87 325is to 24valve wiring help

[samiam3356]

Your tach and diagnostic connector don't work, right? You should also be experiencing a soft cut at upper rpms in 1st and 2nd gear, which might not be that noticeable.

1. x20 pin 24 goes to C104 pin 3 (WT/YL): you are correct
2. x20 pin 14 must be spliced into a wire coming from the C3 connector on the back of the cluster, at pin 26 (BR/RD). The 413 DME requires a vehicle speed output in order to maximize performance. If you don't hook up this wire, you will get a soft cut at upper rpm. Pin 26 should be in one of the four corners of the connector, as it should only have 26 pins in total.
3. x20 pin 20 goes to C104 pin 1 (BK) This will get your tach working.
4. C101 pin 6 must be connected to x20 pin 22 in order to properly power the diagnostic connector. Otherwise a Peake tool won't power up correctly.
5. It's strange that your 87i has a pin 15 in the C101, which would go to 30h on a 3 terminal starter. Most early model cars did not have a pin 15, instead unloading the electrical system through pin 18 with the ignition signal.

Is this correct thinking still? I thought this had to do with the O2 sensor. Tried hooking up a Peake tool over the weekend and it didn't power up. Also saw another thread that said you need to wire a power source to the diag port. Didn't know if that will handle it as well or not. Had the harness converted to plug and play by friend because I suck and hate wiring shit. Anyhow,now I'm wishing I would have taken the time to learn how to do it myself. Kinda backing into it at his point.

[rThor432]

^^ I actually think that my co-worker hooked the power cable up to that, and didnt leave it loose, now that I think about it...

[Apex381]

haha something like that but it wasnt plastic. It was a metal nut but just to hold the power block. It wasnt actually hot.

[FredK]

Ah, you mean one of those 10mm nylocks that hold the cable to the firewall? :p

[Apex381]

Heh well it doesnt "go" yet. Still need to finish welding exhaust, hook up driveshaft, put euro bumpers on, and modify and hook up shifter linkage.

But yeah we thought that one of the bolts on the power block was ok to hook cables to but it turns out its just a mounting bolt and has no power whatsoever lol.

[rThor432]

^^The same thing happened with my swap. Another tech from work was hooking up the power to the starter, alternator, and power block and for some reason thought that one of the power cables was unnecessary.

I have no idea what was going through his head.

Glad to hear it goes!

[Apex381]

We cranked up the engine today!! Turns out that half the harness had no power because we had it hooked up to the wrong bolt on the power block. Doh!

Thanks for everyones help

[asubimmer]

lol well even w/ the x20 pin 7 wire snipped, it gets power when cranking. I don't know where its getting the power from as I didn't wire it into anything. It seems like the ews is killing us. He has the black/violet ews pin 7 wire.

[asubimmer]

bahh this is getting really annoying. I checked power at fuse 11 when the keys are in the off position and we get 0 volts, good. But when the keys are turned into the on position I only get only 2.2 volts. The rest of the fuses are getting their full power. I guess this is one of the reasons, hopefully the only, why we aren't getting fuel.

This is making appreciate how easy my swap was...

[Apex381]

OK I messed around alot tonight and wired up the c104. The harness wiring we did matches yours and yours starts so we think we're good to go on the harness. I guess the next step is switching out the crank sensor and see what happens? There is still NO FUEL. very very frustrating

[Apex381]

Beau,

This is he chart I used to wire up my OBD-1 S52 in my '87 E30. As long as you have the C104, I dont think that there are any differences between the body harness connection for my eta and your 'i'. Try it out. All I'm missing right now is the tachometer, and I think that's due to some hack wiring from the E36 harness to the C104.. (my hack wiring).

e30-e36
pin 1-pin 25 alternator
pin 2 oil level static-(not used on e36) (you can wire the oil level sensor up to this wire)
pin 3x (nothing here)
pin 4-pin 12 coolant temp
pin 5-pin 23 oil pressure (i need to double check this)
pin 6 e30 o2 sensor relay power, goes to nothing
pin 7-pin 21 Starter input (e30 side should have two wires, just tie them both in)
pin 10 dynamic oil level (not used on e36, once again, you can wire this in if you want)
pin 11-pin 19 SI reset function
pin 13-pin 13 Fuel pump relay
pin 15-pin 15 unloader relay
16x
17x not used
pin 18-pin 18 Starter
19x not used

pin 24 on the e36 goes to the red/yellow wire of the c104
pin 14 on the e36 goes to the black wire of the c104
pin 20 of the e36 goes to the wire on the back of the instrument cluster in the circuit board with the green covering that snaps onto the cluster.

Good luck!

Thanks alot Ryan! I've checked and double checked everything but the wiring harness so I'm starting to think that thats it. As soon as ASUbimmer shows up tonight he and I are going to get busy going through that.

[rThor432]

My diagnostic connector does work. I havent hooked up the speed signal(Pin 14), although I added in a good length of wire so that I would be able to when I get around to it. I've got pin 20 running to the black wire of the C104, but I think my embarassingly hacked wiring to that point is causing the problem. I did the wiring at home and not at work, so I ended up crimping 3 or 4 odd lengths of wire together to reach the C104.

The pin 24 - to - C104 pin 3 is wired up correctly though.

Also, for what it's worth, I didnt look up the pins and make that chart. That was copied from one of Etasport's posts that I saved in my favorites when I was doing the wiring. It matches the Project Orca wiring (I've got access to that disc) and one other wiring diagram for the '86-'87 car I looked up.

I just kind of got the car running and I've been extremely busy, so no time to finish it up. I just drive it around for short stints when I feel like it. I'm doing no track days for a couple of months, so unfortunately no rush.

Thanks for the helpful info though! Definitely useful, and much appreciated.

[FredK]

Beau,

All I'm missing right now is the tachometer, and I think that's due to some hack wiring from the E36 harness to the C104.. (my hack wiring).

pin 6 e30 o2 sensor relay power, goes to nothing

pin 24 on the e36 goes to the red/yellow wire of the c104
pin 14 on the e36 goes to the black wire of the c104
pin 20 of the e36 goes to the wire on the back of the instrument cluster in the circuit board with the green covering that snaps onto the cluster.

Good luck!

Your tach and diagnostic connector don't work, right? You should also be experiencing a soft cut at upper rpms in 1st and 2nd gear, which might not be that noticeable.

1. x20 pin 24 goes to C104 pin 3 (WT/YL): you are correct
2. x20 pin 14 must be spliced into a wire coming from the C3 connector on the back of the cluster, at pin 26 (BR/RD). The 413 DME requires a vehicle speed output in order to maximize performance. If you don't hook up this wire, you will get a soft cut at upper rpm. Pin 26 should be in one of the four corners of the connector, as it should only have 26 pins in total.
3. x20 pin 20 goes to C104 pin 1 (BK) This will get your tach working.
4. C101 pin 6 must be connected to x20 pin 22 in order to properly power the diagnostic connector. Otherwise a Peake tool won't power up correctly.
5. It's strange that your 87i has a pin 15 in the C101, which would go to 30h on a 3 terminal starter. Most early model cars did not have a pin 15, instead unloading the electrical system through pin 18 with the ignition signal.

[rThor432]

Beau,

This is he chart I used to wire up my OBD-1 S52 in my '87 E30. As long as you have the C104, I dont think that there are any differences between the body harness connection for my eta and your 'i'. Try it out. All I'm missing right now is the tachometer, and I think that's due to some hack wiring from the E36 harness to the C104.. (my hack wiring).

e30-e36
pin 1-pin 25 alternator
pin 2 oil level static-(not used on e36) (you can wire the oil level sensor up to this wire)
pin 3x (nothing here)
pin 4-pin 12 coolant temp
pin 5-pin 23 oil pressure (i need to double check this)
pin 6 e30 o2 sensor relay power, goes to nothing
pin 7-pin 21 Starter input (e30 side should have two wires, just tie them both in)
pin 10 dynamic oil level (not used on e36, once again, you can wire this in if you want)
pin 11-pin 19 SI reset function
pin 13-pin 13 Fuel pump relay
pin 15-pin 15 unloader relay
16x
17x not used
pin 18-pin 18 Starter
19x not used

pin 24 on the e36 goes to the red/yellow wire of the c104
pin 14 on the e36 goes to the black wire of the c104
pin 20 of the e36 goes to the wire on the back of the instrument cluster in the circuit board with the green covering that snaps onto the cluster.

Good luck!

[Apex381]

not totally sure, I would guess its an m50 out of a 93' 525it