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Misfire on cylinder three

Tiny
MONEYSAM83
  • MEMBER
  • 2015 CHRYSLER 200
  • 3.8L
  • 6 CYL
  • AUTOMATIC
  • 130,204 MILES
Okay. The lead tech changed the spark plug and ignition coil, still misfiring we checked the fuel injector with noid lights, and it is good on that. The ignition coil is brand new. Today I did a compression test I got 150 on cylinder 3 and 120 on cylinder 1. The difference between the two is cylinder 3 looks like the spark plug isn't firing cylinder 1 spark plug is blackish but cylinder 3 spark plug is new. So it could be that. I do not know. Please tell me what you think. The compression readings are as follows: cylinder 1,120. Cylinder 3, 150. Cylinder 5, 120.
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Wednesday, October 23rd, 2019 AT 7:23 AM

9 Replies

Tiny
STEVE W.
  • MECHANIC
  • 13,476 POSTS
Welcome back to 2CarPros. From your description it sounds like the number 3 coil is either not getting power or the firing signal from the PCM. Testing it isn't hard, the Brown wire with the Gray stripe is a common power feed from the ASD relay for all of the coils. It should show battery voltage with the key on. The dark blue with orange stripe is the control wire for that coil, when the power-train control module wants to fire that cylinder it pulls that wire to ground. It can be tested by using a test light in place of the coil, it should flash when it fires that coil. If it doesn't then follow that wire back to the PCM and check there, it's possible the driver transistor in the PCM has failed if the old coil had failed it may have damaged the PCM.
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Wednesday, October 23rd, 2019 AT 8:03 AM
Tiny
MONEYSAM83
  • MEMBER
  • 32 POSTS
Hey man, thanks you were right. How do I fix it?
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Wednesday, October 23rd, 2019 AT 8:14 AM
Tiny
MONEYSAM83
  • MEMBER
  • 32 POSTS
I need to tip y'all, lol.
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Wednesday, October 23rd, 2019 AT 8:15 AM
Tiny
MONEYSAM83
  • MEMBER
  • 32 POSTS
It was real weak but I saw a little light with my test light on that wire.
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Wednesday, October 23rd, 2019 AT 8:23 AM
Tiny
STEVE W.
  • MECHANIC
  • 13,476 POSTS
Very weak pulse or was it on all the time? If it was a pulse the control signal may be there but not strong enough if it is a constant light then the transistor is shorted.
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Wednesday, October 23rd, 2019 AT 8:35 AM
Tiny
MONEYSAM83
  • MEMBER
  • 32 POSTS
A consistent light.
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Wednesday, October 23rd, 2019 AT 8:35 AM
Tiny
MONEYSAM83
  • MEMBER
  • 32 POSTS
Weak too.
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Wednesday, October 23rd, 2019 AT 8:36 AM
Tiny
MONEYSAM83
  • MEMBER
  • 32 POSTS
At the PCM which pin am I looking for?
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Wednesday, October 23rd, 2019 AT 8:39 AM
Tiny
STEVE W.
  • MECHANIC
  • 13,476 POSTS
Pin 49 in connector 2.
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Wednesday, October 23rd, 2019 AT 11:52 AM

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