Truck suddenly ran crappy a few days after I did an oil change (not sure if related). Engine light came on and got the following codes P0304, P0305 and P0306.

Replaced all the plugs, wires and cleaned MAF with same results. Some carbon fouling on plugs 3,4 and 5. I hear a more pronounced ticking (could be injectors, ticking goes up with rpm). I'm not to savvy to take out the throttle body and inspect injectors. Don't seem like I have a vacuum leak.

Anything else I can check? Any suggestions before I bring it to a shop?

 

Sounds like your coil pack went bad and it's not getting enough spark on cylinders 3,4, and 5, thus the carbon fouling.

 

thanks for the reply...

I tested the resistance of both primary and secondary windings according to the repair manual.

primary resistance between ignition coil 4 and 1,2 and 3 are within .3-1.0 ohms

secondary resistance coil 1 (cyl 1 and 5) coil 2 (cyl 3 and 4) coil 3 (cyl 2 and 6) are also within 12.8-13.1 ohms

I however already ordered one ($80) just in case. Any other suggestions?

 

The PO30X codes means "engine misfire detected." I would think that codes P0304,P0305, and P0306, would mean you have misfiring cylinders on cylinder 3,5,and 6. So with that said, I think the new coilpack should take care of it.

If it doesn't, look at your plugs and wires. It is possible that even NEW plugs and wires can be faulty straight out of the box. Check the continuity of the plugwires, and for the best replacement plugs stick with OEM Motorcraft.

 

I did replace plugs with OEM Motorcraft and wires with AC Delco replacement. I will surely post what turns up next.

Thanks for the support!

 

Good luck with it.

 

Replaced the coil pack today, no change. Truck still runs like crap. I did a hand over hand checking for vacuum leaks, still no luck. I'll try to borrow a compression tester to see if my cylinders are shot and a noid light to see if I have injector problems. Just my luck!

Any thing else I can test/check? Thanks.

 

Hmm, sounds like you're doing the right steps in finding the problem. The ticking could be most likely clogged injectors, or it could even be a mechanical problem. Please keep me informed as to what you find. Best of luck.

 

Pull the new plugs on cylinders 4,5,and 6.Compare them to the other new plugs on the other bank.Do you see/or smell gas on them?Excess black soot? Reply back with your findings.

 

Haven't got the chance to tinker with my truck yet due to work and will be on travel next week. The plugs for 1,2,3 looked ok. Plugs 4,5, and 6 had a light coat of carbon a little bit wet and smells like fuel.

Thanks for the help guys. I need it!

 

Sounds like you're getting little to no fire to cylinders 4,5,and 6. Try changing the wires to Autolite Professional Series, or Motorcraft wires.

I've heard alot of of people say they had a bad misfire with some different types of wires. Personally, I've had good luck so far with the Autolite Professional Series wires and Motorcraft plugs that I installed a couple days ago.

If I'm not mistaken, and I think I'm not, AC Delco parts work better on a Chevy than a Ford. Autolite and Motorcraft replacement plugs and wires work best with Fords.

I think the problem is your wires IMO.

 

I like the Autolite wires too.
Use an ohm meter and check resistance on the wires for that bank.Post your findings.

 

This is what I got. Whick ones are good? What are they suppose to read?

OLD WIRES (OEM original)
4 - 12 k
5 - 13 k
6 - 10 k

NEW WIRES (AC Delco 8mm)
4 - 1.2 k
5 - 1.1 k
6 - 1.4 k

* in kilo ohms

 

Wow! Those new wires sure look good! Where did you find AC DELCO wires for a Ford?

 

Bought them from a local automotive store.

ACDelco Part # 16-826B.

Why the big difference in resistance between OEM and aftermarket? Should I get a bigger spark with the new ones with almost 9k difference? (OHMS LAW)