I just completed a tune up on a '03 Ranger with a 3.0L V6. Replaced the spark plugs, plug wires, air filter and an oil change and it ran rougher than before. Checked all the plugs and wires to make sure it was all right and it was. Took it up to autozone and had them run a diagnostic on one of those readers and found out the cam sensor was bad, so I replaced it. It ran rough at first still, but it did seem to smooth out a little. The idle did still seem to be rough, but was idling at around 900 rpm. Was at 1100 at first. I think it may work self out, but really don't know. If anyone has any idea of what it could be, please let me know.

 

Andrew if it ran fine before then it is pointing to a problem with either a plug or a wire or a vacuum line shifted loose installing said parts.Start over and pull the plugs and check to make sure the gaps are correct and check for a cracked porcelain,if you dropped a plug that would cause a problem also make sure all the new wires are seated properly.Check all the vacuum lines adjacent to the area you were working for cracks or looseness.
Good luck man!

 

I would see if you can get them to read the codes again, and write down the numbers.

Bad Cam sensor(CPS) might cause a rough idle but just not very likely, the CPS reports the Cam position to the computer, but the computers main sensor for spark and fuel injection timing is the Crank position(CKP) sensor,
If CPS wasn't matching CKP then computer would turn on the CEL(check engine light) and just ignore the CPS, you would notice a slightly lower MPG, but not much maybe .5-1 MPG loss.
CPS was added to improve MPG, engine should run fine without it.
3.0l Cam syncro shaft should be replaced every 80,000-100,000 miles anyway, it runs the oil pump and these shafts have been known to seize up, at speed this would trash the engine, as engine would continue to run but without oil, opps


You could clean the MAF sensor, and at 10 years old the Ford vacuum lines start to crack and leak, carefully check the PCV valve hoses, the underside of any elbows.
small vacuum leak will cause a rough idle.

Does the engine run fine above idle?

 

At first after I replaced the cam sensor it seemed to idle smooth. When I went to drive it, it started acting up but the longer I drove it,the more it seemed to smooth out and act better. There is still something wrong, just can't put my finger on it. The check engine light is out on it. Really if the speed is under 50 MPH it's fine, it's when you try to go above is when the problems start.

 

In the end it was just a couple crossed wires, not sure how I messed that up. I replaced them one at a time, oh well.....things happen.



Nope I was wrong, they wasn't crossed after all.

 

This is putting up a red flag to me. it's been like this since we got it.

This end came loose, dunno if it effected anything.

 

They don't add "extra" things on engines, 100% of every hose, wire and part is needed at some point.

Don't know what those are without a wider angle to see where they are on the engine.

 

Never said they was extra. In fact I know what it is, what concerned me was the crap on the hose. These parts are located on the back side of the engine on the drivers side.

 

I hooked up a scanner tool and it was tellin me there is a misfire on the number 2 and number 5 cylinder and it's not a crossed wire.

 

"This end came loose, dunno if it effected anything."

"In fact I know what it is,....."

So is that hose part of the PCV system??
Gunk on hose was most likely put there to seal an air leak.

A leak in this system will cause a lean mix in engine.

Cylinders 2 and 5 don't share the same coil, they are the center cylinders in each bank, but are not "matched".
'03 should have sequential injection if CPS is working, and you would get a code if it wasn't.

I would check the spark plugs in 2 and 5, see if they tell you anything, also swap them with 1 and 6, or any other working plugs, but write down what you swap.

And give the PCV system a good looking over, if above photo is a PCV hose then the others will probably be starting to crack, and that will cause misfires

 

I'm taking it to a shop tomorrow to get it all straightened out. I'm tired of trying to figure it out.

 

Found out the problems. Needed a new coil pack and the hose replaced that goes from the back of the intake manifold to the PVC valve. The hose had to special ordered from Ford. So get that tomorrow then when I get back from vacation put it on and all shall be right.(I hope).

 

Yes, for some reason mechanics are always replacing the coil packs on the 3.0l, maybe bad design or maybe just easier to do than testing it.
Keep your old coil if possible.

Yes, post 2000 Ford vacuum hoses, especially PCV hoses, tend to start cracking after 10 years, so yours are due.

The PCV hose isn't "special order", it is "out of stock", they are having to replace them faster than they can get them, just FYI.

 

Finally got the Ranger running and driving like it should. Still had a vacuum leak, had that fixed.

 

Next time you think you have a vacuum leak, give the engine bay a couple of shots of Carb cleaner. Engine will sputter if something isn't connected properly.

Worked wonders on my sisters GM 3.8L.

 

Turned out that the new coil pack was installed wrong. Don't ask how, cause I don't know. Plus the number 5 cylinder had no compression. So it's going back to where it came from. A F-150 super crew is in the near future to replace the Ranger.

 

I believe '03s were in that range of 3.0l engines that had the floating valve seat issues, which could be the issue with #5