Similar problem
Hey guys,
New member here just starting to really learn about my truck. I have a haynes repair manual and some basic mechanical knowledge. I can see through searching that this topic is well-documented, but I thought maybe I was missing something simple in my symptoms that a more experienced mechanic might pick up on. I don't think it's the problem quoted above because my misfire is at low revs.
My 2001 3.0 V6 FlexFuel Automatic Ranger with 140,000 miles on it sat for two weeks in heavy rain. I had never had a misfire issue before that. When I started it up it had a rough idle and continued to misfire in the low revs (up to about 2000) but seemed to smooth out as I reached higher revs. The problem is growing worse and it misses consistently at low revs and with small throttle applications, but seems to run a little smoother with a leadfoot and higher revs.
I changed the spark plugs a few months before this started happening and didn't have any problems with them, so I don't know if those would "go bad" after working fine for months.
I changed the fuel filter when the mis first appeared and that smoothed it out for a day until I drove it through a rainstorm and the misfire re-appeared, then disappearing again when it dried out.
Today I thoroughly cleaned the MAF for the first time. It was filthy and after cleaning it the truck fired up, purred beautifully and ran great for 5 minutes at all different RPM's, then the misfire came roaring back same as it was before.
I guess I'd just like to know if this sounds like something you've seen before and if I should buy a new coil, plug wires and plugs, or should I check compression.
I did get one code out of it for a misfire on cylinder 5, but that has since gone away and has not reappeared, even though the misfire is still clearly there.
Thanks for giving this a look!
Jon