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Some problems are more complicated and require a disciplined approach to ruling things out and getting to the actual root cause of the problem, then you perform a targeted repair and then verify the fix. Most people are not wired for this kind of work but that's what problems like this need. I just finished helping a complete novice find a wiring fault in her headlight circuit. She did numerous replacements and when that didn't do it, two local shops refused the job, then she came to us. We did it together on this forum with a low end multimeter but it took over 100 posts as she learned. I will stick with you but you have to have the will and discipline. Sure it can be the PCM, coil ICM, plugs, wires, distr, cap, crank sensor, ignition voltage, countless ground, wiring faults, connectors, shorts to ground,.... That why you need to test your way through this. Stabbing at it is painful.
There is plenty to do but I want you to find the ignition leak because it can narrow things down. Here is the factory manual on your code:
I gave you a link earlier that had a generalized flow for finding a misfire which is very similar to a low power complaint. You walk through all of the possible systems starting at the top of each subject and drilling down when you find trouble. You always look for clues like codes and bug zapping to give you a better starting point than just the top of the flow chart, to get to it faster. A problem like yours is a hundred to one shot if your guessing and stabbing at it. All of the best mechanics and trouble shooter hired guns work like this. When you bring in a truck like yours to a shop they hire a guy like Paul Danner (Scanner Danner) often times to come in and walk through a process like this, then they do the repair and eat his fee because they just need the truck gone and a happy customer. Another guy who works like this is Eric at South Main Auto, his you tube videos are great.
Ok I will mist the wires again and I'm sure I'll find the leaking wire but hows that gonna point us to the problem. If it did it with the old wires and does it with the new one ? Does that mean I need to go buy a 3rd set of wires ?
Because it depends on where and why. Is the coil still arcing? Is it in the distr? If its wires, are they routed wrong/chafed/burned? Is it just one wire or many. If one what happens if you swap them? No you don't replace the wires unless they are physically damaged or test bad with a meter. What do the plugs look like? If we don't find anything useful once the bug zapper is located then its on to that P0351 flow chart and after any problems there are corrected then a more generalized approach to misfiring and poor engine power which also has a long but testable list.
Regarding P0351 or any ignition problem you start with power and grounds then continuity testing of the signal wires then looking at the signals (plus or minus on the order). Like I said there is plenty to do except stabbing at it. I realize you don't have a shop full of gear (high voltage probes, O scopes, Snap On scanner, shop manuals, ...) but much of this stuff can be done with simple capability. That said a sophisticated shop with a talented diagnostic guy would already be looking at high voltage and low voltage waveforms, power and ground levels, ... but those guys make the big bucks. We have to improvise here.
Yes an ignition wire was hacked. One of the wires that go to the coil for the car starter shouldn't I be focusing on making sure that wire is ok ? Do you have any diagrams so I can trace and test the wires for the coil and ignition module back to the pcm ? It's the tach or signal wire that was messed up that goes to the coil. I disconnected the car starter wire that was going to the coil and repaired the wire. There is only 2 wires that go to the coil. It's a three wire plug but they dont use the middle terminal of the plug.
There should be no starter wire involved in the ignition circuit, I don’t even know what purpose that would serve.
I would like to have determined why you have ignition arcing and correct that first but You have a certain order that you would like to work so let’s work with your plan. Yes the wiring needs to be in good shape. I would measure the voltages on the pink wires for the ICM and coil as well as the quality of the ground for the ICM. Then you can check the wht/blkwire between the coil and ICM and the wht wire between the pcm and the ICM (resistance and shorts to power and ground). Move the harnesses around when you are doing these checks. If that all looks good then you monitor the signals on the two signal wires. I will help you with any of these tests if you need guidance.
you decide what coil you want to use but then leave that choice alone until we find your problem
09-17-2021, 08:10 PM
