M42 Full Rebuild now won't start

[bmwman91]

Doesn't the cluster get the RPM readings from the crank position sensor? Maybe it's a faulty sensor, have you tried swapping it out with a different one?

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Not directly. The CPS signal goes into the ECU. Then the ECU spits out 2 pulses per revolution (1 pulse per 180 degrees) to the cluster. So, the ECU is feeding junk signals to the cluster for some reason. Either the ECU is bad, or it is getting a bad CPS signal, both of which seem unlikely based on what the OP has replaced. I am still thinking that no chip or a bad chip is installed in the ECU case. All maps AND program executable code are on the chip, so if it is missing or bad, things are not going to work right.

Was the ECU swapped with a new one, or a used known-working one? A new one might not have a chip in it, and if it was used, maybe the previous owner pulled out the chip beforehand?

[nk1221]

Ohhh I see! My bad!

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[theTBLACK]

Not directly. The CPS signal goes into the ECU. Then the ECU spits out 2 pulses per revolution (1 pulse per 180 degrees) to the cluster. So, the ECU is feeding junk signals to the cluster for some reason. Either the ECU is bad, or it is getting a bad CPS signal, both of which seem unlikely based on what the OP has replaced. I am still thinking that no chip or a bad chip is installed in the ECU case. All maps AND program executable code are on the chip, so if it is missing or bad, things are not going to work right.

Was the ECU swapped with a new one, or a used known-working one? A new one might not have a chip in it, and if it was used, maybe the previous owner pulled out the chip beforehand?

It was a used, known-working one. I'll crack it open and see if there is a chip inside.

Will keep you guys updated.

Could the AFM cause a non-start in any way?

[MVincken]

It was a used, known-working one. I'll crack it open and see if there is a chip inside.

Will keep you guys updated.

Could the AFM cause a non-start in any way?

My m42 ran (barely) when I had forgotten to plug in the AFM.

Are you sure you´re getting fuel in the cylinders?
EWS blocking the fuel signal by the ECU perhaps?

[MVincken]

And what about youre injectors?
When I rebuilded my m42 I let them be cleaned by my engine builder, but at the time I installed them about 3 months later 3 were already jammed again.
Best to delete the upper intake manifold, take a 12v battery and check if they "tick"

[theTBLACK]

And what about youre injectors?
When I rebuilded my m42 I let them be cleaned by my engine builder, but at the time I installed them about 3 months later 3 were already jammed again.
Best to delete the upper intake manifold, take a 12v battery and check if they "tick"

I'll double check all of that and report back!

[5Toes]

does the CEL engine come on when ignition is first turned on, that light comes on when the DME powers up. check that.

spark plug order, check that.

crank pulley on in the correct orientation?

[nk1221]

Have you gotten anywhere OP?

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[theTBLACK]

does the CEL engine come on when ignition is first turned on, that light comes on when the DME powers up. check that.

spark plug order, check that.

crank pulley on in the correct orientation?

Had to tow the car to a shop closer to me. Spark plug order is correct. Crank pulley is right. Timing is spot on. Will check the CEL

[theTBLACK]

Have you gotten anywhere OP?

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Nothing yet. Fuel, air, spark, no fire. Nobody can figure it out. At this point, I'm thinking its faulty wiring or sensor somewhere

[bmwman91]

Is there any possibility that you got the crank damper wheel installed incorrectly, like 180 degrees off? It is supposed to align on a dowel on the front output flange thingy (which is supposed to align to a woodruff key in the crank snout). Parts 6, 7, 8 and 9...were they all in there correctly?

http://www.realoem.com/bmw/enUS/show...diagId=11_4319

[Balleristic31]

Any chance you swapped the coolant temp sensor plugs around? Or the coolant temp sensor is bad?

I had an issue similar to your's on an m20 car that ended up being a coolant temp sensor being faulty causing a no start even with all the other proper conditions (fuel, spark, etc..)

[theTBLACK]

Back at it again - cranking and wants to fire with fluid but no dice. Also, the plugs are dry. Probably injector issue. What would cause that? I've tried different DME.

[varg]

Have you cranked with the fuel rail out (injectors attached) and verified that they are firing?

The injectors get +12V from the main relay via the red/white wire coming from Pin 87, leading to the harness box under the intake manifold. Verify +12V is present here when cranking. The ECU grounds the injectors in pairs (1&3, 2&4) to fire them. If you haven't, check continuity of the wires between the injectors and the ECU (pins 3 and 32)

[theTBLACK]

Here is what I did today.

1. I noticed the spark plugs were dry - so I double checked the fuel lines. They were on backwards this whole damn time, so I swapped them. Then they were wet. Fixed that issue

2. I checked for spark and I'm getting it.

3. Checked compression. Good on all cylinders.

4. Stomp test again - no codes.

5. Tried to different DME. No difference.

Any ideas where to look or diagnose next?