mapleleaf1773

Ok guys, I have 2 fords. My f150 and an explorer.

My explorer (wife explorer) is giving me problems. The explorer forum sucks and i get no help from them. If you guys would be so kind to help that would be appreciated.

2006 Explorer, 4.6 engine 141 k miles. My engine is missing and running rough period. I have mis fire codes on cylinder 4 and 6. I have gotten a P0174 code for A/F , but not currently, just the two mis fire codes currently.

I changed all the plugs, helped a little but still misfiring
Tested all coils, primary and secondary resistance, they are good. I've rotated them out still misfiring the same cylinders.
I traded out the fuel injectors 4 and 6 for other cylinders, still same misfires on cylinder 4 and 6.

also the P0316, first 1000 revolution code, but that just started. I'm about at my wits end after one of my plugs broke and I had to spend $545 and a week with 1 car at the dealer to get it out.

what to do next? Ideas? Thoughts?

white89gt

The next thing to do would be swap injectors around, or just replace them. They could ohm out correct, but still be plugged. How did the plugs look in those cylinders? Lean?

mapleleaf1773

I swapped fuel injectors with other cylinders but still same mis fires on cylinder 4 and 6. Plugs are original, in bad shape, all of them. I dont know the difference looking at the plugs, just they all needed replaced.

I ohmed the coils not the injectors. And I replaced 1 of the coils on cylinder 4 brand new and no change. I replaced all the coils 1.5 years ago.

white89gt

I am confused here....

------------------------------------------------------------------------------------------------------------------------------------------------------------

EDIT: Here is a good reference chart to "read" your plugs:

mapleleaf1773

They were original plugs and were worn badly. You expect that from 141k. I dont think anything else from the chart applies to them, just worn.

white89gt

OK.... but first you said you changed the plugs, then you said they are originals still.

Which is it?

mapleleaf1773

sorry, they were original and at 141k I changed them, which was 2 weeks ago.

here is a picture of one of them. I'm not a plug expert. You think worn only or?



other side of plug below

white89gt

That tip is melted...... yes, they are worn. HOWEVER, it could also be a sign of being too lean. So we are all on the same page, you've changed all of the plugs, swapped coils from cylinders that are not cylinders 4 and 6, and you've also swapped injectors with cylinders that are not 4 and 6?

mapleleaf1773

correct

white89gt

Does the motor make noise? If you've ruled out fuel and ignition as being a problem, the next thing is mechanical. Have you done a compression test?