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1997 Jeep Laredo Repair Question


Topics covered: Ignition coil, Engine, Battery.
Mileage: No information provided.

Asked on April 9, 2008

1997 Jeep Laredo P0351 - again..


Been having problems lately with vehicle stalling or losing power to a near stall. Within the past 2 months I've replaced the battery, thermostat, -ignition coil-, cap, rotor, pickup coil, crankshaft sensor cleaned the throttle body with carb cleaner (there was a lot of carbon deposit build-up), had cables/contacts cleaned with electrical cleaner & the last thing I tried was backing out 1/4 of the way the 2 torx screws from the cover of the pcm (I read in a fourm that the screws from the factory are too long and can cause a short in the PCM). Which backing out the screws seems to have worked at least for several weeks no stalling or hesitation. Although I still noticed a low and rough idle accompanied with slight bucking/shudder on occasion when vechicle shifts gears (I believed this to be a vacuum leak). It still hasn't stalled, but today it did loose power to a near stall for 2-3 seconds, no check engine light. Luckly I had my scanner with me hooked it up planning on recording data if the problem reoccured (which it didn't). Except it showed the DTC P0351 (Fault at ignition coil primary/secondary) not a pending code either, I'm not sure why the check engine light did not come on. What I am thinking is that possibly I need to back out the screws from the pcm a little more. Maybe the screws were still in a little too far and still caused a short. I didn't know though if that short in the pcm would cause a false code, the ignition coil is less than 2 months old so I seriously doubt it's already gone bad. So can a short in the pcm cause a false DTC? What else could cause the DTC P0351 other than the ignition coil?

A few day after originally writing this, the Jeep did stall at a red light but cranked right back up. Hooked it up to the scanner when I got home and was now getting P0351 and P0300 (multiple/random misfire detected)
Avatar Asked by 24csintx

Answer

Replied on April 14, 2008

Check the PCM ground wire (BLK/Tan) on the right side of the engine, clean it up and resecure it...

Tiny Answered by merlin2021 (expert)
18,145 answers provided
Replied on April 14, 2008

I'll try that either tonight when I get home or tomorrow. Do I need to disconnect the negative battery cable first?

Tiny Response from 24csintx
2 questions asked
Replied on April 14, 2008

I would...

Tiny Answered by merlin2021 (expert)
18,145 answers provided