Ignition question, No longer thinking ignition.... Options

[1bwilson]

So I lend my jeep to a friend for a few weeks and go to drive the celica and find it running rough. After a bit of investigation Ive found the im getting a very small amount of spark from wire #4. So I did the usual swap plugs, new wires, new cap, new rotor...... Nothing, still a weak spark. So weak infact that its not even igniting fuel. Im not excited about the possibility of a pinched wire somewhere in the harness and im even less excited about the idea that I may have to hunt it down. So before I start pulling things apart let me go over what I know it isnt and hopefully someone will see light where I cannot.

out of the 3 mains (fuel,spark and air) Ive already figured out its the spark.

Its only happening on the #4 wire

Its not the plug, wire, distro cap, rotor as I have replaced them all.

I AM getting spark but its very weak and at times not there at all.

The old cap had burn/spark marks on the pins accept for the #4 one where it looked almost new.

I cant see any pinched wires but that doesnt mean something has worked itself loose some where out of view.

An option I have is running a MSD 6a ignition (if that would bypass my problem), Ive had one sitting on a shelf for almost 5 years and I have yet to install it. The only problem is I dont know how/which diagram to use for the install.

/discuss

This post has been edited by 1bwilson: Aug 29, 2008 - 7:04 PM

[DEATH]

Wouldn't this indicate a problem within the distributer itself since he's getting strong spark to #'s 1-3? If he's getting strong spark to the distributer and to each cyl but #4 I would think it must be internal to the distributer and not back on the coil which is providing enough spark for the other cylinders.
I really suck at explanations on things like this [But I can diagnose and fix them ] - Hopefully you understand my train of thought here.