All right, Ford gurus, here's your chance to one-up the local Ford service department. I've had my 2000 Explorer XLS with 62k on the 4.0 OHV in there twice (not to mention another shop) and no one can figure out what's wrong. It's not fun paying $130 dollars for them to say, "yep, it ain't running right."

What it does is miss badly, and it codes a misfire, first couple of times on #6, now on #4 (that's a very broad code). It gets the converter coming from the driver's side of the engine cherry red from running rich, so much you can smell the burning. Orginally, it appeared to do it worst on long trips, and it would be fine for a while on short around town-jaunts. This last time, however, even a short trip was too much.

I noticed it running a little weaker than normal some time back, so I put new Bosch Platinums in it. Shortly after, it started this bad miss. I took it to a shop, and they found a burnt spot in a plug wire (also said one of the plugs was loose, egads), so problem solved. Wrong. Did the exact same thing, thought it was a clogged converter, wrong. Ford thought it was a faulty injector, but they check out. All diagnostics checked out (even with the motor running like &$%*), and after they put the plugs back in, it again ran fine for a while. There's no real pattern to when it stops (diddling with the plugs/wires seems to do it), and the pattern to when it starts (long trips) seems to no longer be in order.

The Ford tech said the problem was probably the Bosch plugs, that it needed Motorcraft, but my opinion is that he was grasping at straws. Would a Bosch plug go dead and stay dead for 100-plus miles, just because it's not the cheap Motorcraft brand? I'd like to think it's that simple.

Help! I have to get it fixed, if only long enough to get it to the nearest dealer.........

 

i know you dont want to hear it but i've read and heard that those bosch platinums will cause problems on the explorers...you may want to put motorcrafts in and your problem should go away

 

Laytham, this almost has to be a coil pack problem. On the 4.0 ohv the number 4 and 6 cylinders are adjacent to each other on the coil pack. You probably have an intermittant short between the two coil terminals.

You might try pulling the #4 and #6 wires off the coil pack and clean the terminals. If that dosen't help, then the short is probably internal, and will require a new coil pack.

The #4 is the right rear coil terminal, and the #6 is directly forward of it (looking from the engine front).