Pulled all the plugs and dried them and cleared out the cylinders. It has a completely new ignition system now and it has good spark off the coil but random weak spark at the plugs. Doesn't make any sense to me.. I have to say for the first time in 20 years of working on cars I'm stumped.

 

Random weak spark at the plugs in most times is a bad cap/rotor/wires or wrong plugs. Put the old ign parts back on and try that.

Edit; I have messed up a couple of rotors installing the cap and bent the one metal piece over on top of the rotor.

 

Old stuff won't work. They destroyed the distributor trying to figure out what was wrong and drilled new hole cuz they broke an ear off trying to screw down the cap when they didn't have it on right. And broke the rotor button cuz the cap wasn't on right. So basically everything that was on it is junk. It has 8mm wires on it and champion plugs. Don't remember then number and I quit for tonight and went home. I'll b back at work in the morning and will look at it again. I'll check back in the am for any new ideas. Thank you for all the help so far.

 

Is the cap/rotor on there now new? Or, did it come with the distributor?

 

Its new

 

At this point I'm leaning towards a pcm... Don't really know what else to try

 

If you are getting good spark from the coil, but lousy spark at the plugs.... gotta be something in between. Recheck wires, cap, rotor, and firing order.

 

^^^ +1 pcm will not be a cause for weak spark. It has to be in the cap me thinks. I will go back through the thread and see if the ckps has been changed out.

 

Ckps has been changed twice.

 

I'm going to test the coil again for the strength of the spark and if it's good I'll try another set of plugs and wores. The cap and rotor appear to be in perfect working condition. I just put a new one of them on last night too...