1992 B2600 miss fire
 

When I start truck blue spark intermittenly comes out where cap attatches to distributor and grounds to distributor. I replaced the cap and rotor thinking I had a cracked cap but the problem persists. The issue seems to be worse under lower RPMs and the colder the engine. It doesn't completely go away when the engine warms up but it doesn't seem to be as bad. The truck will idle fine with just an occasional miss fire. As soon as you start to depress the accelerator the engine begins to fall on its face missfiring more frequintly until it reaches higher rpms. Is there something inside the distributor that can go bad and cause this problem and if so can it be replaced or do you have to replace the whole distibutor.

Electricity follows the path of least resistance so i would replace the plugwires.