I'm having a similar problem. My scanner won't show when I try and adjust my
Distributor. Another problem if anyone can help me with if possible. My truck runs fine in the morning, but in the afternoon when I'm on my way home it starts jerking real bad. Checked for misfires but it has none. If I punch it, it blows black smoke. I checked my plugs and right bank were all black. I've changed maf sensor and no change. Has anyone experienced this problem before?