I have a 98 4.6 Expy that just turned 90k. I've already had the typical Cylinder 4 misfire and fixed all that stuff, so I know how the truck feels when it has a skip.

This week I have noticed a "skip" that seems to get progressively worse. The only problem is that its not throwing an error code like a typical misfire does. It mainly happens going uphill or when accelerating from a stop. The truck definately does not have the ***** that it usually does. Any thoughts?

My gut feeling is that my fuel filter is crudded up and should probably be changed. I just put in a nice full tank of Mobil gas tonight on the way to work and the skip feels less frequent and less severe. It could purely be co-incidence though. Hopefully the fuel pump is not crappin out on me....

 

My 98 XLT 4.6L had the same thing happen today. It did eventually illuminate the check engine light. I checked the code and it came up with P0304, which is #4 spark plug. Once the engine is cool, I am going to set out to change the plugs and wires starting with the hard ones first.

My question for the forum is since I don't have the COP, what is the main cause for the #4 going bad in the 4.6L.

Todd
1998 XLT 4.6L

 

hy my name is jaap i changed my nr 4 coil today i didn t have an error but when i took out the coil it was all rusty so was the threat of the sparkplug i thin k the cause is that the end of the upper radiator hose where it is attached to the heater was leaking it was leaking on top of the coil so it was rusting and made the coil breakdown i also have a question :i checked every resistant off each coil they where between 7.5 and 8.5 ohms but they should be 5.5 ohms is this a problem should i change them all it is a 5.4 lariat from 98 thanks jaap goodluck steve

 

I have a 99 EB EXPY 4.6L, 90K and after replacing the plug wires for another plug, I noticed that the #4 wire was chaffing against something and was arcing to ground. That may be your problem.

Also had a recent #2 misfire code, I checked the wires for spark by quickly removing the wire at the ignition coil and replacing…, checked plug gap… Come to find out that, the metal contactor was screwed down tight to the ceramic, but still moved side to side…that was causing the misfire...

Advise for changing plugs:

1. Buy a Haynes manual, it helps somewhat, and is better than nothing. You can also buy a ford factory repair manual on CD from EBAY for ~ $12, and is very helpful.
2. Search this forum for helpful hints on plug changes, type of plugs, Etc.
3. Buy some mechanics gloves.... your knuckles will thank you !!!!!!!,
4. Be patient, spend some time looking around the engine , looking with a hand mirror to find the plug hole, feeling, moving hoses and thinking before turning the wrench.
5. Buy some ratchet extensions, I got mine a Harbor Freight (cheap, but they work)…..IMO..IT IS A WASTE OF TIME TO PROCEED WITH OUT THE EXTENSIONS… I tried it the first time with tools on hand and took 10x times as long trying the half azz it…

6. From the plug, use a deep well plug socket, then a 3 to 4 inch extension, then a U joint, then what ever is required to allow the ratchet to turn freely above hoses, and other things. For the #4 plug, you will probably have to use a 4 to 6 inch extension (after theU Joint) to clear the hoses and then install the ratchet head so you can work under the windshield overhang, so you will have about 30 degrees of turning freedom. For other plugs, you can probably uses a longer extension to raise the ratchet above everything and allow 360 turning.

7. Install with di-electric on the plug connector and boot. Use anti seize compound for the plug and torque to spec(I use a $15 torque wrench fro Harbor Freight, once again, cheap, but it works), I think the spec is ~ 8 to 13 FT LBS….

Good luck, it sucks the first time, but gets better after that.