95 Camaro 3.4 mystery ARCING
 

My 3.4 Camaro started to lose power and developed a random misfire. I popped the hood at night and noticed that all the wires were arcing. After replacing the plugs and wires the car ran pretty well for a couple of days and then started the misfire again. I looked for arcing again and noticed fire jumping from the tensioner pulley, alternator pulley, and AC compressor pulley to the serpentine belt. Electricity will arc from the belt to the tip of my finger if I hold my finger about a sixtenth of an inch above the belt. It will even arc to a my plastic cig. lighter.....What the heck? I've replaced the wires and plugs twice, I've replaced all the coil packs and the ICM, I've checked all body grounds to be good and I've rerouted the plug wires several times with no change.......I also added plastic insulation to the wires.......still the same annoying misfire and arcing. The arcing seems to be noticeable on the passenger side of the engine...the only wire I can see arcing, sometimes, is number one cylinder, in various spots along the wire and near the plug. I was having problems with starting the car for a while. It would spin over but act out of time/buck/stutter and take a second to actually crank. that problem was fixed when I changed out the battery cable ends. The same symptoms as leaving the ICM plug nearest the driver side unplugged........I'm wondering if maybe the PCM or the Cam sensor could cause arcing?

Any and all ideas would be welcomed :)
I'm losing my mind over this mystery arcing..........

can you get it scanned for trouble codes? that might help save time and bucks. cam or crank sensor are what comes to mind.

I replaced the PCM about three years ago with a used one I bought online. It doesn't and never has stored trouble codes for some reason. Never flashed it but the car has been fine up until now.

This sure sounds like and engine grounding issue. In the past I have had almost no luck explaining electrical diagnoses over these forums so I gave up. Here is one last try. Using a voltmeter put the ground lead on the negative side of the battery and the positive lead on a bare connection on the block. Check for a voltage reading. A good volt meter should pick up something like .01 volts with the car running if everything is working right. That is due to the resistance in your ground cable. Iif it reads .5 volts or higher you have a problem. You can repeat this test to the body in several places and lastly you want to do the same test between the engine and the alternator to see if there is a grounding issue there.

A double check is just to add temp jumper wires everywhere. I would add a 12gage (or lower) jumper from the battery to the block, from the block to the alternator and from the block to the body. The jumper wires was just a add-on the GM engineers used to make us do when working on just about every “that don’t make sense issue” even after we tested the grounds. I guess they did not trust our testing.

I've spent hours hooking up jumper cables in various locations checking for grounding issues and it doesn't change anything. I'm going to try to use several diff. jumper wires and see if anything changes. I'll let ya know

check ground strap, goes from block to frame.

High voltage from an ignition system wants to find a path back to the battery and it is going to jump around till it gets there or damage something in the process, such as punching a hole through an ignition wire, burning out a coil, or zapping you. When sparks jump all around as you described, it means that the proper path to ground via the spark plugs is compromised. As Gorn and Craby indicated, the engine may not be properly grounded back to the negative side of the battery. You can test it as Gorn described, or connect a jumper cable from the negative side of the battery and a rust free spot on the engine block and see if the light show ends.

I've ruled out it being a body ground. I even removed the body ground strap and cleaned the both ends were they bolt up. I also added an extra body ground from the block to the frame. No change. I did check the voltage of the center wire going into the cam sensor while the car was running and it was pulsing at around nine volts. I've heard that spinning the crank by hand will read from 4-7 volts...... anyone know if the nine volts means it's bad?????? I appreciate you guys chiming in and trying to help...I need all the help I can get on this one.

you should have a ground wire under the belt tensioner,,, sorta, its in the front on passenger side of motor,,, to the bottom. also a ground junction on the passenger side fenderwell next to the power juntion box. may want to check them wires out to see if any look damaged.

The cam sensor is not your problem. What you need is good ground path between the battery, body, and engine.