Engine replacement, not getting any spark to the plugs?

Tiny
WJS4777
  • MEMBER
  • 2012 SUBARU FORESTER
  • 4 CYL
  • 4WD
  • AUTOMATIC
  • 116,000 MILES
It is not getting any spark to the plugs. A 2011 2.5 engine was put in a 3012 car. Does the ECM need to be reprogrammed?
Thursday, April 6th, 2023 AT 8:27 PM

4 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,536 POSTS
It could be can I ask if the crankshaft angle sensor is hooked up, here is the location so you can double check it. Also, we should run the codes to see what comes up.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

This guide may help as well:

https://www.2carpros.com/articles/car-not-running-advanced

Check out the images (below). Please let us know what happens.

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Friday, April 7th, 2023 AT 11:04 AM
Tiny
WJS4777
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  • 2 POSTS
  • 2011 SUBARU FORESTER
  • 2.5L
  • 4 CYL
  • 4WD
  • AUTOMATIC
  • 123,456 MILES
I put a 2011 engine in a 2012 car the same size engine in a Forester and it will not fire. I have checked every sensor, every plug and every coil pack but it still just will not fire, why will it not fire? So, it will not run, spark, or even try to run, it has power to the coils, to the cam sensors, to the crank Senors, but it is not firing. Why? It's driving me crazier than I already am.
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Friday, April 7th, 2023 AT 3:04 PM (Merged)
Tiny
AL514
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Hello, the first thing I notice is that the ECM part number from 2011 to 2012 is not the same. Although I don't see many (if any) differences in the wiring harness to the ECM, the programming I'm sure is different. Ill post these part numbers for you and go over the ECM connectors and wiring again, but you could check and see if you are getting any fuel injector pulse, hook a test light to battery positive, and out of all the fuel injector wiring there should be one wire the same color which is the power feed, Looks like a red wire, the other wire you should see a dim pulse on the test light hooked to battery positive while cranking. The fuel injectors are ground side controlled, so the ECM should be pulsing your test light the same. You will probably find the (control) pulse is missing.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

https://www.2carpros.com/articles/how-to-test-a-fuel-injector
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Saturday, May 4th, 2024 AT 1:48 PM
Tiny
AL514
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Is anything setting codes? The 1st diagram is the 2011 ECM part number, 2nd is 2012, and depending on the build date, the camshafts changed part number about halfway through 2011. So it might be that the camshafts have shifted or repositioned slots in the camshaft plate. I'd be surprised no cam/crank correlation codes are setting. But if the cams are actually in time with each other, that might be a programming factor. But different part numbers mean there's some change in the cams. If there's no injector pulse at all, I'd go over your Grounds again as well, just to be sure there's proper ground between the battery and engine block. The Intake camshaft waveforms to Crankshaft waveforms look the same.
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Saturday, May 4th, 2024 AT 1:52 PM

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