Hey everyone! I have a '99 Ranger XLT automatic with 3.0 ffv6, 91,000 miles, and it's recently been running like crap and really jerky on the interstate (or anytime when I accelerate - also rough idle). It was REALLY bad today and it finally threw a check engine code. Took it to autozone, it said that there was a misfire in my number 6 cyllindar. I glanced over the plug wires and didn't notice anything that looked damaged.

Well the weird part is this: I first noticed it *slightly* around a week ago. It acted a little 'jerky' when it was shifting from first to second and I was afraid it was my tranny. Well it seemed to go away altogether... until today when I almost didn't make it to school because it was running so rough. However, on my way home from autozone, it ran PERFECTLY. No problems whatsoever. So HOW could it go from barely drivable to perfectly fine just like that?

Anyways, I'm taking off work tomorrow to do some catch-up work on it - gonna change the plugs, the fuel filter, and the air filter - maybe the oil. So is there anything special I should do about the misfire in #6? Or should I just see if new plugs does the trick? (and can anyone plz shed some light as to how my truck went from rough to smoothe in an instant?)

I greatly appreciate all help! Thanks, everyone!

(PS: what plugs should I get?)

 

It may be a ballpark time to go ahead and replace all the plugs and wires. There may be a chance the wire will tear apart if it is pulled off, so replacing them may be a good idea. Be sure to use double platinums.

 

Was Autozone able to identify any more codes than just the #6 miss?

 

Others may disagreee, but IMO it's time for a tune-up. Regarding choice of plugs for your flex fuel 3.0L, this may help you decide:

https://www.ford-trucks.com/forums/s...d.php?t=240714

Change the plug wires, too. I recommend Motorctaft brand, or you can go with Prestolite wires from CarQuest, or even Beldon wires from Napa, to name a few decent brands.

Change the air and fuel filters. Run some fuel injection cleaner through. I would also clean the MAF sensor:

https://www.ford-trucks.com/forums/s...hreadid=126093

Then take the cable off the negative battery terminal for 20 minutes to erase the codes. Drive around and see if the same problem persists. If it does, then you have to think about other things causing the misfire, such as a bad fuel injector or even a a failing camshaft position sensor.

 

I agree with the plug wires and don't go with the cheapies. If you search some of the other threads you will find that the if you buy wires according to price, you will be buying them again.

 

I had a similar problem on my 99 4.0L.

Would act out in the morning when things were damp or in driving rain on a light engine load (up hill).

Mine also was the #6 cylinder, turned out to be a cracked spark plug insulator.

If you have a spare one lying around, you might exchange it & see if that clears things up.

If so, maybe new plugs are in order as the guys suggested. If you save up for new plugs be shure to heed the advice of those other 3.0L owners on plug heat range type.

If you don't have the cash to replace the wires, at least check their resistance, replace any out of spec ones. DON'T use bad wires on new plugs.
If you have to, visit the salvage yard & test to see if you can find some good ones from a low mileage engine, until you can afford a new OEM set.

Just some thoughts if funds are short.
Any port in a storm, RIGHT!!!!!!

 

Are Autolite sparkplugs any good? Every ford dealer I've called want's $7.38 a plug. :/

I guess people have been having problems with Bosch plugs in their fords, so I'll nix that.

 

I have used autolite, with no problems, but I like Motorcraft for the money. Motorcraft is made especially for Ford cars and trucks. You can't put Motorcraft in anything but a Ford.

 

motorcraft and autolite are both made by the same company, (Honeywell, i think)

 

Bumping this thread because I still haven't fixed the problem. Here's an update:

Since posting here last, I have changed the oil and filter, I have changed the fuel filter and the air filter, and I have changed out all the plugs.

The only thing I haven't done is change the plug wires.

When I did the rest of my upgrades, I wasn't able to come up with the greenbacks to afford the wires, so I didn't. Now I have the money to do so, but before I go ahead with that...

---
What are *all* the likely problems that could be causing this miss-out in cyllindar six? I've checked my wires and I can't see any burns or anything which would indicate them being the cause. So I don't just want to buy new ones if these are okay. What other specific ways could I check my wires for their integrity? And what was that about cracked plug insulators? I don't know what that is or how to ckeck/fix that.

So yeah, needless to say, after all that work the problem has not gone away! The plugs helped the general firing a LOT, but there's still somethign else really wrong here. It idles SO rough now... it's crazy... hardly accelerates sometimes. (btw, the new plugs helped it, so I know I put those in right and all, but the main problem is something else)

I greatly appreciate all help and advice! Thanks folks!

 

A quick test would be to replace the #6 Plug wire... maybe from a second car for a test. If it is bad you will notice it quickly, if not you haven't spent money for wires you don't need. Next would would be the fuel injector not working. Other problems would be valves/gasket leaks/cracked heads... not likley and heavy work.
Dave

 

Thanks for the quick reply!

Okay.. now... Do I need a special type of plug wire to put in my Ranger to test that out? The only other vehicle I could swipe one off of would be a '94 Oldsmobile and I have a feeling it wouldn't work based on the differences. (But I don't know too much about the workings of cars as you guys can tell)

And as far as the fuel injector not working, would that cause only one cyllindar to act up so bad while the others are fine? My truck has thrown a trouble code three different times since it starting acting up, and every time it is the same code: 'Missfire in Cyllindar Six' so I'm thinking that sorta isolates the problem. But what would a bad injector mean? Is that a difficult/expensive fix?

I really appreciate the help. Thanks!

 

I would just switch the 6 wire with one of the others and see if the miss follows it, could also be an injector or an intake leak near that cylinder.

 

Go back to Auto Zone and have them pull the code/s. Write it/them down. Com back here with the specific code # example: PO1443. Many people here have much experience with this and can help guide you from that point much better.

 

Yes I agree. So far it sounds as though you have been doing the "change this and hope it works" method. Nothing wrong with that necessarily - sometimes its all you got to go on. But in this case I would definitely pull the codes and post them. That truck has some serious diagnostic tools on board and if it was something complex you'll find it right away.

Plugs, wires, fuel filter, air filter - all of that stuff is ordinary equipment and I just don't see it causing your problem. I've run '68 Dodge one ton duallies with 1/2 inch of caked on dust in the air filter (refuelling vehicle for the farm equipment). I've run my Chevy Cheyenne with 7 plug wires.

What do the plugs look like? Normal color but severely worn? All black and slimy, blistered, reddish, cracked? That will give you a good indication of the mechanical condition of the cylinder. If 6 was bad, the spark plug would show that. Consider that before dumping lots of cash into replaceables.

Just speaking my mind, from experience as someone who nickeled and dimed himself to death working on my 1980 B2000.