Need help getting M20 to fire

[chrisracer79]

Hi everyone, I swapped an M20B25 into my 2002 (woo hoo) and I'm trying to figure out why the motor won't fire. I've been through the ETM and bentley manuals trying to track down the problem - conducted just about every electrical test I could think of - I even went through a great article that BavAuto has on diagnosing no start issues.

Ok here's what I've done. I'm hoping someone can point out the obvious to me....

1. Spliced 2002 harness into the M20 harness using the C101 connector for various connections (charge, fuel pump, oil pressure, ecu power, etc). It all appears correct....;)
2. Test Fuel Pump direct to +12V - PASS
3. Test fuel pump relay control - Jump pins on 36+2, ground pin 3 on motronic connector - PASS
4. Test main relay control via motronic connector - PASS - relay clicks
5. Main relay was suspect since voltage was present on 30 and 86, but not on 87 when key in START, so I replaced it.
6. Test Fuel Pump Relay voltage between 85 and 86 with ignition on - FAILS
7. fails on 12v test between pins 85/86 with ignition on
8. Starter is working - engine tries to turn over, no firing.
9. Spark test FAILS
10. Fuel injector pulse FAILS
11. Coil has power
12. ECU is getting constant +12V from two pins
13. ECU grounds PASS
14. I can trigger Main Relay and Fuel pump and injectors by jumping pins on the ECU connector
15. CPS passes OHM test
16. Starter input to motronic FAILS - This is pin 27 on the DME connector. According to the ETM This is coming from the OBC relay box - which I don't have. I don't know what this is used for, other than the OBC.

So a few things to note. Charcoal canister is deleted. Purge valve connector is not connected to anything. I'm assuming it's the purge valve connector....

I don't have a spare ECU to rule out the ECU.

ANY help is greatly appreciated.

_C

[jeffnhiscars]

I'd check jlevie's sticky in the DIY section.

[chrisracer79]

I'd check jlevie's sticky in the DIY section.

Thanks Jeff for the sticky. Certainly helps. The only base I haven't covered is PIN 27 - start signal, which I knew I wasn't getting, but I didn't know what the DME did with it. Now I know.

I need to figure out how best to get the start signal from the ignition switch to pin 27 at this point. Fun wire tracing time!