e30 m50 OBD2 swap - fuel injectors not firing.

[BeardednBimmer32]

Hey fellas I'm having a hard time wrapping up this e30 m50 OBD2 swap. I'm getting spark, fuel, I'm pretty sure everything is grounded accordingly but, the fuel injectors are not firing. I swapped with known working injectors, still nothing, tried 2 other DMEs still nothing. Swapped the crank position sensor three times... Nothing. I am at a loss at this point, I'd hate to tow it to a shop because I know it's something simple. Anybody familiar with this issue or have some advice on what I can look at? I had the harness professionally rewired, running a Siemens DME from Kassel Performance. O2 sensor in, fuel pump working, coil packs and spark plugs firing (sprayed choke fluid and fired right up!).

Thank you,

BnB32

[hoveringuy]

Start with the fuel pump. Is the fuel pump triggering when you engage the starter?
Yeah, the fuel pump isn't related to the fuel injectors except that it demonstrates that the ECU recognizes that the engine is turning over (and the CPS is good..)
The injectors should have constant +12V. I'll wire a 12V LED in to check things like that. ECU completes the ground.
Does it want to fire with starting fluid?

[sweet3]

Yes, try using starting fluid to make sure eveything else is working like it should. This will confirm that the compression, spark plugs, coil packs, and other sensors are in working order. This will also confirm that the ecu has had the EWS deleted.
Assuming the engine DID start with starting fluid, make sure the fuel pump relay is activating. With the relay socket labeled 1-9, Pin 6 will be constant +12v. Pin 8 will be switched +12v. If the relay is not activating, double check those 2 wires.
If the fuel pump IS activating, the only other possibility would be the fuel pressure regulator and/or the Cam/Crank sensors. The Cam/Crank sensors should throw a CEL code.

Other things to check:
- Are your fuel lines backwards (Forgot about this. It's a very common mistake)
- Ecu Fuse near the rear battery (In-line on battery cable)
- Ground on engine mount arm

[Northern]

What fuel rail are you running?

I mean does your fuel rail have a FPR, or if you're running the stock OBD2 rail did you keep the running losses valve(+FPR)?

[M3Gonz]

I just started another thread similar to this, with an OBD1 M50 swap. Hopefully we'll find some answers.