85 318i with 93 525 M50 *issues*

[SiGmA_X]

With the help of the forum, we've got the engine installed and every thing working perfect, except the wiring. It won't start, and nothing at all happens. We followed Addissimo's e34 wiring diagram, and used the BMW ETM for the 318i. We are getting no power at the fuel pump relay nor main relay. The starter does click over but absolutely nothing else happens.

I hope some of you guys can help me out here! Here's a copy of my wiring diagram.

Thanks in advance.


The yellow lines are the ones that I'm not sure about, being speedo and tach. That isn't the problem I'm up against today, but if someone knows which wires are the ones I'm looking for, by all means speak up :)

[Mr Deagle]

those two wires are in c104 in the glovebox, engine speed is for the rpm on the dash, and speedo signal is for the obc mpg/average/max function

[SiGmA_X]

Is C104 a 3 pin connector with two of the wires being green and black? I lost my piece of paper that listed the precise colors on that connector, but I think it is that one...

[Mr Deagle]

yes, it has 3 wires, one is tach, one is speed, and the other is the obc code function

[SiGmA_X]

Sweet! Being you have some early model cars what do you use for a check engine light? I am under the impression there isn't one on the early cluster, is this correct?

So I have been thinking about this a bit and will be checking all power and grounds tomorrow, but I did that today already. Being the relays are getting no power, that means a pretty early wiring problem in the harness, I'm guessing. There is a connector on the e34m50 harness that I have no idea about. I will take a picture and post it, but it is located on the DME/relay section of the harness, and is 2 rows and maybe 16-20 total pins. It contains a few thicker (2.5mm maybe) red/red-striped wires and perhaps some other colors, I wasn't paying much attention to it prior to this problem. Does anyone know what it is? I will post a picture shortly.

[SiGmA_X]

Okay so we had to replace the fusible link, and the car still doesn't start. The DME and relays proved to be good, we started with them in my car.

[SiGmA_X]

Interesting development. The motor will not turn over by hand. We used a 4 foot breaker bar, and no luck. When the motor was out of the car, we turned it over countless times, no problem. When we mated the flywheel (We are using an m20 84 Eta G260 + Flywheel/Clutch/Starter) to the motor, the engine still turned freely and there were no clearance issues with the flywheel/oil pan/block like some people have mentioned. We mated the tranny and dropped it in, but did not check to see if it would turn over - Whats the point if it did and the clearances were fine, right? Ha.

Any advice?!! What happened to make it unable to turn over???

[SiGmA_X]

AH HA! So you know how some people said the G260/early-Eta flywheel hits the e34 oil pan? Well, it sure does. I'm surprised as to why it didn't hit prior to this when I torqued and tested it, but when my friend whose car it was installed the fly/clutch/tranny, it sure as hell does hit. We just pulled the tranny off (Took all of ~30min ;)) and the problem was obvious. We're going to take the fly in to be shaved tomorrow, and the problem should be solved.

Now to deal with the wiring... Still no fuel pump turn-on, etc. What wires are we forgetting to hook up?! Can anyone help here, please??

[SiGmA_X]

We dropped the tranny, shaved the oil pan and put the tranny back in, all in about 2 hours, with downtime to check torque specs, practice shave the spare pan we had, etc :)

For anyone who says its easier to pull the motor to change clutch/tranny, they are partially right. You do need to use a cherry picker but don't have to remove the motor entirely. The easy way to do this is to disconnect the motor mounts, lift the motor off the mounts and move it forward until the motor is pretty much as far forward as possible, then lower it down so it is just above the subframe. Then impact away and your bolts will come away. Its pretty simple really, you just have to do it the right way :)

We now have the tranny back in the car, all bolted up, and I'm taking my friend to a Blazer's game. By the time he gets back, I should have the starter in and the motor back on the mounts, and hopefully the wiring will be closer to working. I'll keep you guys posted.

[Addissimo]

The only thing I can really think of with your wiring woes are the power and grounds. Don't be afraid to cut away some of the protective sleeving to make sure you're actually connecting a ground (brown) to ground, and power (red) to power. The e34 harness makes it a little complicated, I believe there are two grounds, one power, and the power that goes to your starter. When people are having this problem, it seems like its usually power/ground related. The power line to your fuse box is connected, right?

did you do the fusable link thing with the fuel pump?

-Addis

[NZM50SWAP]

I used addisimo's chart and it worked perfect for me...

89 320i - 92 e34 525i engine

Sounds like you may hav a grounding problem

[SiGmA_X]

Well I got it fired up tonight!! Here's the wires I used. I will post a complete list of what wires we use all-in-all once the car is done and has an OBC :) Not exactly sure what was wrong with the wiring, I think it was the starter and/or ignition wires on the X20 side of things. It works now!

X20.12, "coolant temp" -> C101.4
X20.13, "Fuel pump relay" -> C101.7, to fuse #11
X20.14, "Speedo" -> green to C104 -> green
X20.15, "Starter" -> C101.8
X20.20, "tachometer" -> black to C104 -> black/blue
X20.21, "Ignition switch" -> C101.10
X20.23, "Oil pressure" -> C101.16
X20.25, "Alternator" -> C101.1

[EtaSport]

For a check engine light, run a 12v bulb off of the interior lights or something then ground it through pin number 8 (i think its 8 on the x20, but i know its a gray wire). That wire grounds the check engine light when a code is set. I've been too lazy to try this and I havent really been sure what amp lamp to get, something super low though.