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98 PCM - Sudden Grounding Issue

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Old Jul 25, 2016 | 04:53 PM
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Default 98 PCM - Sudden Grounding Issue

Hi Guys,

I am currently having my 98 Camaro tuned by a reputable tuner local to the greater Atlanta area. I brought the car to them last week and swapped out 28lb injectors in favor of 42lb injectors. I didn't start the car after installing the 42lb injectors as I didn't want to cause any trouble with incorrect fueling.

The day after dropping the car off the tuner calls me to tell me that the car will not run without the laptop OBD II harness attached to the OBD II port. When the tuner pulls the laptop OBD II harness out, the engine dies. The tuner chased it down to the PCM ground and has installed a jumper on the OBD II port in order to ground the PCM. The car runs fine with the jumper installed.

Here is my question: What went wrong? Did I cause the issue when installing the injectors? I was very kind to the injector harness and I have removed and installed the injectors a few times thru the years. Is there a critical ground in or near the injector harness? The tuner said he checked out all of the grounds throughout and they were all OK.

For what its worth, I've never had an electrical problem in the car. Ever.

Please share any thoughts you may have.

Thank you,

Last edited by 98cherrySS; Jul 29, 2016 at 10:42 PM.
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Old Jul 28, 2016 | 02:07 PM
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Bump.
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Old Jul 28, 2016 | 03:21 PM
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The issue is in the harness. I have had this same problem twice.
Have them check and clean all grounds. There are 3 main grounding points in the engine harness, fixing those will get rid of most problems, but there are several grounds to check.
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Old Jul 29, 2016 | 07:30 AM
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Originally Posted by MontecarloDrag
The issue is in the harness. I have had this same problem twice.
Have them check and clean all grounds. There are 3 main grounding points in the engine harness, fixing those will get rid of most problems, but there are several grounds to check.
Thanks brother. I'll be walking thru this entire harness when I get the car back.
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Old Jul 30, 2016 | 03:36 PM
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Well, it was a broken ground on the back of the drivers head. $2 fix.
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