Re: 2000 4.0 ranger/missing,headache
That is odd that your plugs are getting fouled, something is amiss for sure. Has anyone run the codes on it? That may well tell you what the issue is, perhaps bad timing or perhaps bad spark plug wires, have they been replaced since you bought it?
Has anyone checked for any vacuum leaks, how does the truck perform otherwise when the plugs aren't fouled and how many miles?
I had a missing issue and that was caused by a badly severed spark plug wire and that caused the idle to fluctuate and the engine to run rough, all other plugs were coated w/ a dry brown stuff but the fouled plug was kind of oily if I recall from not firing due to a bad wire. I have the 4.0L V6 with 218K+ miles on it.
The same rough/fluctuating idle was also caused by a vacuum leak and yes, the check engine light came on every now and then but since the leak was fixed, all's been fine.