My wiring thread- No fuel, no spark, here are my ideas

[Roysneon]

I have a 93 touring with a 94 E36 M50tub25. It cranks over but does not start. I have the relays grounded and the fuel pump and ignition power is connected properly.

The fuel pump does not prime with key 'on' and doesn't run with key turned to 'start'. There is power to the coil connectors with ignition on but they are not firing. I'm assuming there is constant power to one spade, a ground is another and the third one should be to fire the coil?

I'm also assuming that the DME fires the coils based on a signal it gets from the crank sensor.

I think my problem is due to a ground issue. The three relays are grounded. I have one going from the mount arm to the frame rail like it was stock, the one near the DME that plugs into the harness above it under the dash, I just need to know what else should be connected?

I'm quite sure I'm missing one on the valve cover, what else?

[eurosport22]

do you get a cel when you turn the key to no. not start just on

[Roysneon]

Nope. I'm guessing that means bad DME or bad grounds. There is power coming to the DME through the big connector.

[Roysneon]

The DME has power going to it from 4 pins, but no CEL. Would a bad relay do that?

[Roysneon]

I'm trying to find out what it's doing and why but honestly I don't know how relays work or what it's supposed to do to make it run.

[shiboujin]

you plugged things in wrong. it isn't getting a crank signal. Get a diagram and match the wire colors to the sensors.

[Roysneon]

Does that explain the no CEL ever? Thanks for the reply.

[shiboujin]

ECU has no crank signal so it never knows to check if it needs to throw CELs.

[Roysneon]

That seems



Most logical

[shiboujin]

I troubleshot a car with problems exactly like yours. Same everything. We had the crank sensor plugged into the ICV and vice versa.

[Roysneon]

There's no power to crank sensor at any of the three contact points in the connector. I'm assuming it should have power to the yellow one, black is ground and the other really funky coloured one is the signal back to DME?

[e30shmobberr]

There is a site called wedophones, click under manuals, find auto manuals and select the year of your engine. This will help you figure out exactly what each wire is.

What are you using in terms of the x20/c101 connectors?

[Roysneon]

I used this chart to get me started, then checked all the M50 things off of the wedophones ETM to be sure.



There is no ETM listed for my car (93 touring with an M40) listed so a late e30 318is is as close as I could get.

[e30shmobberr]

are you splicing? or using an adapter?

[Roysneon]

Splicing the C101 from my old engine in place of the X20 from the M50.