No fuel, but cranks well!

[BustaRhymes325i]

Trying another ECU tonight. Where am I checking this ECU ground at, if anyone knows off hand?

[BustaRhymes325i]

Ok heres where im at:

Tried another ECU (has a blue label 506 on it) which yields spark and fuel (at least I think, because it is backfiring). The problem is, when I depress the ignition key, it cranks like 5 cranks, stops, then cranks 5 cranks, stops, and will occasionally backfire in there somewhere.

When depress the ignition key with my 413 ECU (the original ECU in this thread), it cranks and doesnt stop until I stop pushing the key down. So it behaves completely normal, just isnt giving me spark or fuel.

Idk im stuck at a crossroads. Seems like I almost need to try a 3rd ECU or something. Maybe I am overthinking this?

[jrdeamicis]

Cranking is not sensor dependent. Its a simple circuit for the starter.

Start with why its not spinning all the time. Look for +12V at the body connector. C101.

If you are getting +12V on ignition @ the starter. I would go with your starter is acting funny.

[BustaRhymes325i]

Cranking is not sensor dependent. Its a simple circuit for the starter.

Start with why its not spinning all the time. Look for +12V at the body connector. C101.

If you are getting +12V on ignition @ the starter. I would go with your starter is acting funny.

Ok, Ill check this. It just seems odd though that when I swap between 2 ECUs that it cranks normal for one ECU, but not the other.

[jrdeamicis]

So, what does it do when there is NO ECU and you are cranking?

[BustaRhymes325i]

So, what does it do when there is NO ECU and you are cranking?

Not sure, Ill check though.

[BustaRhymes325i]

Just an update, car is running:

When I did the swap, i was converting from a 92 325i NV. I reused the crank wheel in the front, which is apparently different from what is needed on my S50, so this was issue 1. Issue 2 may or may not have been my crank sensor. The car started with this one, but it was bashed up for some reason. Issue 3 is that my 413 ECU did not start the car, but a loaned shop ECU will start the car. I believe all other wiring, etc was correct.

Consider this resolved. Thanks for all the help.

[Adrian_Visser]

Why the hell were you trying to use a 413 on a NV engine? you need a 403 or 406 DME

[BustaRhymes325i]

Why the hell were you trying to use a 413 on a NV engine? you need a 403 or 406 DME

No no...

The car used to be m50 NV, im currently swapping to s50, that is what is in it currently, and the motor this thread is based upon.

[M-technik-3]

Well the wiring harness from a NV engine does not actuate the vanos so how is that getting power?

[BustaRhymes325i]

Well the wiring harness from a NV engine does not actuate the vanos so how is that getting power?

Switched harnesses as well. I had the correct harness throughout this thread.