crankshaft sensor not working properly

1995 ALFA ROMEO GTV
300,000 MILES • 2.0L • 4 CYL • 2WD • MANUAL
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JOESAMPLE
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  • 4 POSTS
Stop working when the engine heats up.
Sep 16, 2019 at 5:08 AM
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KASEKENNY
  • Experienced Mechanic
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Hi,

Have you replaced the sensor? Crankshaft sensors are Hall Effect sensors and when they get hot they actually open the contacts which causes them to not send a signal. The vehicle will then shut off until it cools down.

If this is what yours is doing you need to replace the sensor.

https://www.2carpros.com/articles/how-a-crank-shaft-angle-sensor-works
Sep 16, 2019 at 11:08 AM
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JOESAMPLE
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Hi,
I have replaced sensors two times (Facet/EPS) but the problem is still the same... and the vehicle works fine again until it cools down.
Sep 16, 2019 at 5:34 PM
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JOESAMPLE
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PS... the engine runs and starts even when it is hot but.. if you increase the RPM (video).
Sep 16, 2019 at 10:58 PM
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KASEKENNY
  • Experienced Mechanic
  • 18,907 POSTS
Hi. The video did not come through. Can you try again? Thanks
Sep 17, 2019 at 7:41 AM
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JOESAMPLE
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Take 3: video plus attention! I hold the accelerator pedal in one position.
Jan 12, 2020 at 9:17 PM
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KASEKENNY
  • Experienced Mechanic
  • 18,907 POSTS
You have an issue either the the coils for the ignition or the injectors, or lastly the control unit. This light coming on each time the RPM drops indicates this as an issue.

Unfortunately we don't have a service manual for this vehicle so I can't give you the specifics but I would start with checking for codes and then hooking up a scan tool to see what the sensors are doing when this happens. I suspect the o2 voltage will give us an idea on what is happening.
Jan 12, 2020 at 11:01 PM
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