Need help desparately with 93 3.4L V6
edit: or possibly corrosion on the contact point between the module and coil pack
Last edited by 98TA_vert; Apr 8, 2006 at 05:54 PM.
Here is how to check, while the engine running, using plastic plyers, take a wire off the coilpack (any of them) and visually inspect the color intesity of the spark. Is it bright blue/white, or is it a little more dull in looks, less intense compared to the rest of them. Which ever coil pack has the weaker spark, thats the one you replace.
This motor uses "waste-spark" technology, this is where both cylinders on one coil pack will fire, one will fire on the ignition stroke, and the other will fire on the exhaust stroke. You may even find that one wire/coil is not firing at all. Hold the wire close enough to the coil this way the spark will arc from wire to coil, if held to far, you'll get nothing.
Also look for any "burn" marks on the coilpack case. This will indicate the coil is grounding out inside of itself.
I've replaced many of these coilpacks on various gm models.



