[chuzz]

Are you sure you're getting the button seated properly? IIRC, there's a notch in the shaft that has to line up with a knot in the new button.

 

[valiant67]

There could be slop allowing the distributor shaft to move around which could tear up the contacts.

 

[onlyone43]

Just took the 3rd cap off, no burn marks. The cap looked great, yet I still have an intermitting mis at 1600 rpms about 45 mph. No mis when under a load or accellerating. 2 codes, misfire cy 1 and 3.

 

[dana44]

Misfire, with this many miles, when was the last time the wires got changed? I had an 88 Dakota that would develop a miss every other time I changed the sparkplugs and had to change the wires to fix the problem (like four times in its life I owned it), carbon core non-solid wires are not designed to maintain continuity more than a couple times of disconnecting cap or sparkplug connections.

Agree the rotor may not have been seated all the way down, but as a check, pull the rotor on the shaft in an upward direction and see how much it can be raised, check the rise by twisting, see if the rotor is riding up on the cam helical gear, if it does, the housing on the bottom of the distributor could be worn down from scraping can add slop and then start destroying the cap and/or rotor.

 

[Bob Lincoln]

I would do a full tuneup every 50K miles on that engine - plugs, wires, rotor, cap, air filter, PCV valve. Chances are that the wires are toast.

 

[AC TC]

Check the plugs for oil...(intake plenum belly gasket!)
Mine did eat caps and had slight misses when the leads were bad.

 

[onlyone43]

ok gang, replaed all plug wires, spark plugs, rotor button, dist cap. Ran like a champ for 3 miles, then started missing, cyl 3 miss fire code. Have not looked at the plenum belly gasket. Would that cause a missfire? (ALL THE PLUGS THAT CAME OUT WERE CLEAN) Any more thoughts?

 

[Bob Lincoln]

I'm betting then, that the dist shaft is wobbling due to a worn bushing. To replace it, you pull the distributor (after marking the rotor position) and pluck the bushing out of the block - it's driven by the camshaft. They wear and cause wobble as they age. When my brother owned my truck, it sheared the button and the truck stalled on an on-ramp. This was at less than 100K miles.

 

[AC TC]

" Would that cause a missfire? (ALL THE PLUGS THAT CAME OUT WERE CLEAN) "
A leaking bellygasket causes the plugs to foul so if they are clean the gasket is prolly ok.
They also tend to use a lot of oil with a leaking gasket esp when idling.