slant-6 problem

[Brian Hood]

Good evening, everyone! I hope you and your families are enjoying your lovely summers. My wife and I have been very blessed. We have two new wonderful additions to our life: Mr. William Hood and Miss Alana Hood. May God bless you and keep you as He has kept us these last few months.

On a different note, I have a problem with my daily driver. It's an 85 D100 with a slant-6 and an automatic transmission. The other day, as I was driving it, I noticed that it began to miss slightly. As I would get around 55 to 60, it would pop through the carburator and misfire. When I got home, I checked the wires and found that the top tower of the coil had some clear liquid in it, possibly oil. I decided to do a complete tune-up and replace the coil. I gave it new plug wires, plugs, distributor cap, and rotor button. As you look at the pictures of the spark plug, you can see that there's an ashy build-up (not oily) from the #5 cylinder. I did a compression test and all of the cylinders were 120 lbs each. Since this is an electronic ignition in the truck, is there is any suggestions from anyone what I should be checking for to figure out what I'm missing.

Thanks,
Brian Hood

 

[1BadDodge71]

Check the timing,it might be off.And congrats on your new additions:cheers:

 

[66aCUDA]

Are you still running the Lean Burn Computer? What/where did you get the parts? Brands that are REALLY bad quality abound. Pm me for faster response as I'm really busy right now and don't all ways get back to see each thread.
Frank

 

[Backtobasics]

A couple thoughts:
I would look into a valve adjustment, to make sure everything is squared away in that department.
I would investigate the HEI modification. This give a full 12V spark energy into the ignition system, instead of running it through a ballast resistor that drops the voltage.
Seafoam treatment.

I can't be sure why only #5 is mis behaving, but the above will with the recent tune up will help eliminate some areas as problems.

From memory, is there a vacuum port or something that dumps into the #5 runner? Perhaps it is causing the soot?