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No spark from from coil pack cylinders 1 and 4

3657 Views 4 Replies 3 Participants Last post by  RUBI 4 MY MRS
Right I’m at a bit of a loss I’ve got a wrangler SE with the 2.4L and it’s only running on two cylinders, 2 and 3. Replaced the coil pack twice put new wire on and put new plugs in it and I know that there is nothing coming from that half of the coil pack cause when I took the plug wire of the pack nothing changed but when I unplugged cylinder 2 while it was running and lit myself up. Is it possible that the camshaft sensor could cause only cylinder 1 and 4 not to have spark.
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Welcome to the Forum, from Cave Creek AZ.
The cam sensor would not cause this; the crank sensor could if it can’t read the notches on the flywheel for those 2 cylinders but seems highly unlikely. More likely it’s either an open wire from the PCM or possibly a PCM problem.

There are 2 coil control wires (pins 1 & 3) at the coil. Each needs a pulsing ground signal from the PCM to fire its coil as it cranks & when running. Check that since you should be getting it from the coil that is firing but probably not the other one. If that is the case you need to check that wire for continuity from coil to PCM including the connector pin going into the PCM. Make sure that pin is clean & seating properly into the PCM as well as the one at the coil too.
Did some continuity testing on the plug for the coil everything was fine there then I opened up the pcm and found a nice scorch mark on it where something had burned out so that looks like my problem
That's not good! Got a photo??
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