M52b28 swap crank no fire -SOLVED

[ColonelMustard]

So for a quick overview.


I had already swapped the car with a '97 m52b28 and kept it OBDII. The swap ran well for awhile (2yrs) then motor failed so I decided to pull it and drop in a 'new' donor motor. The donor is a M52b28 from a '98. I swapped over my engine harness, coils and kept the same DME that I had reflashed by Markert Motor works. i did all the other refreshes for the motor before dropping it in. (new gaskets, water pump, thermostat, vanos refresh, etc)



I got it all swapped and buttoned up, but on first start it just cranked and wouldn't fire. I also didn't hear any buzzing from the fuel pump like I would before. So now I'm going to check all my power and grounds are hooked up correctly.



My main suspicion is that I'm not 100% sure I have the grounding straps for the ignition coils hooked up correctly. It has the plastic VC, and I put the grounding straps on coils 3 and 6. There is also the ground wire coming from the coil harness that I hooked on the same stud as coil 3 but I'm worried that's not correct.



Does anyone have a definitive picture of how I should the coils grounded?

[e30austin]

Make sure your DME is grounded to the chassis. One of the main grounding points for the engine harness.

[ColonelMustard]

Yes the DME is getting ground. When checking the dme connector I'm getting ground on pins 1, 2, 3, 4, 19, 20, 21, 22, 23, 24, 26, and 31

I terminated some unused connectors in the harness while I was swapping the motors. I terminated the connectors shown in the image, and my main ground is #5 which is fastened to the passenger strut tower. (image below isn't my exact harness)



Verified that the fuel pump works by jumping the relay, main relay is getting power. ICV is buzzing. Next step I'm going to take is to swap the crank sensor with known working one, and check for spark. Any other thoughts or things I should test?

[ColonelMustard]

Solved

Like many other cranking but no start conditions, the culprit was the crankshaft sensor.

It eluded me for awhile, because it wasn't throwing a code and I had taken what I assumed to be a good sensor out of my old running motor (I even checked the resistance, before installing and it appeared within the normal range). After checking fuel, spark, and air with everything checking out correctly, I tried spraying starter fluid in the intake while cranking. It rumbled a couple times and died, but after this it finally threw a fault code saying it was the crank sensor. Bought a brand new sensor and it fired right up.