I have a 2001 Ford Ranger V6 3.0L with 81,000 miles on it. Recently it has been missing under load (acceleration). I have changed the spark plugs, ran fuel injector cleaner through it, changed the fuel filter, cleaned the MAF, and disconnected the battery to reset the computer. Nothing has worked so far. I don't think it is the spark plug wires because I cannot see the sparks at night after misting the wires. What else could it be? Thanks for you time...

 

I'm not a 3.0 expert, but I read where the 3.0 is bad to carbon up after they get some miles on them. The fix was to run a can of seafoam through it. That may not be the problem, but it couldn't hurt and it may help. I know one of the symtoms was loss of power under load, so maybe.

 

Is the CEL on? Do you know which cylinder is misfiring?

Just because there is no visible sign of arcing doesn't mean the plug wires haven't deteriorated.

You should consider doing a compression test.

 

I had the same problem. the insulator on cyl. # 4 was cracked. I replaced the spk. plug ........end of problem.
Just because you installed new plugs......means nothing.....they are sometimes a bitch to install and you may have cracked the porcelan(?) insulator.
BUT.......I GOT A CODE THAT DIRECTED ME TO THIS PROBLEM IN THE FIRST PLACE

 

I also think the wires are the most likely culprit - I've actually taken to changing wires when I change plugs, since that reduces the risk that I have a problem there.

 

Check your firing order! Same thing happened to me last year and that was the culprit. There was no code to be thrown, it ran seemingly OK. I reversed #2 and #3 cylinders and the pistons must not have been very far from TDC (top dead center) when they fired and it wasnt noticable untill either heavily accelerating or when holding a constant speed.

 

When it misfires when under accel does it backfire also or just get jerky? Has it showed any codes? Are you loosing any fluids IE coolant or oil? Have you checked you fuel pressure, is it to specs?