Facetious

I have 1999 chevy express cargo van with the 5.7L in it. Just yesterday as I was driving down the road the check engine lamp cam eon and it started rnnning rough, with loss of power. It felt like I lost a cylinder or 2. So when i got back to the garage, I pulled the engine cover off and began pulling the wires 1 by 1 from the distributor cap to find which one it was losing. I got to 2&4 and when i pulled one of them, ran better, with still a bit of a misfire. I put it back in and pulled the other and the same thing happened. So here is the dilemma. When both 2&4 are plugged in, they both do not fire at all. But, if either one is plugged in individually, they will fire. Code i am getting is P0300. Random misfire in multiple cylinders. I've narrowed the problem to 2&4. Seems electrical/electronic to me. Cap, rotor, plugs, wires check out fine. Any ideas?

stewdogg

I would recheck the wires on cyl 2 & 4 to make sure you don't have any arcing happening from the wires rubbing on the valve cover or something. I have had that happen on multiple express vans. Next I would check the ignition coil to make sure it is not shorting. It is easiest to do this in a very dark place so you can see the light blue colored arcing on the outside of the coil. When you say that the cap, rotor, plugs, wires check out fine how did you check them?