CPS to ICM Wiring

[jmgtp]

I suspect this to be the cause of my no spark condition. I have replaced the CPS and have tried 3 different sets of ICMs (a total of 9 different coilpacks) that all seem to provide spark to my 3.1 engine when tried, so they must be good. The ICM is recieving 12v and ground when the ignition is on and as far as I know power and ground along with crank signal from the CPS meet all the prerequisets for spark (from what I know at engine speeds <400 rpm the ecm has no say in spark). So the issue must be in the wiring between CPS and ICM unless my reluctor wheel in the crank is somehow messed, but really how would that possibly happen.

so the question: the 2 wires from the CPS to the ICM are braided. why? I know the cps generates an A/C voltage so is it some kind of measure to retain signal integrity? I suppose I should be asking my dad this (hes an electrical engineer) but I'm giving you guys a chance first :P

also would length of the wiring make any difference? Gauge of wiring? I have some speaker wire thats maybe 18 gauge or so that I think I will use. The ICM is currently relocated and to do this I did need to lengthen the wiring, but that was done a few years ago and ran with no problems since (and I didnt braid the wires for the cps signal extension but car ran fine). I imagine something in my additional wiring went awry so I'm bypassing it all together and running new wiring from cps to icm.

[brian89gp]

The twist should help reduce the chance of noise being picked up in the wires, if I remember right it is run right next to the power wire from the alternator which is not exactly the most quite wire in the car. I would try just straight wire and see if it starts, if that is indeed the problem then maybe check into some twisted wire.

I have maybe 6' of straight wiring in mine and my car runs, though not very well. The verdict is still out on why though.

Do you by chance still have that metal plate that the ICM mounts to in its stock location? Having the coils moved is all fine and dandy but I'm thinking on putting mine back to the stock location.

[3.4Z24]

if you use speaker wire and it works, replace it as soon as you can. the insulation on speaker wire is crap in the engine compartment. get some wire from an auto parts supplier and twist it yourself. the number of turns per inch isn't critical and it is braided for noise rejection. same reason you should keep your O2 sensor wire away from spark plug wires-it'll mess with the signal.

[jmgtp]

I havent touched the car yet. Its off insurance for the winter so I'm unmotivated. I have another car thats sposta be my winter car and it hardly runs so I'm more concerned with making it right first. I did use speaker wire when I relocated the ICM a few years back, the insualtion didnt seem to be a problem, it is kept well away from the manifold and any big source of heat and has wire loom around it and a 1" diameter coolant hose around that, heat shouldnt be an issue. I will probably end up using regular easily flexible multi-strand copper wire when I do get around to it.