I have a 1999 4x4 4.0l ranger and I have replaced the whole egniton system and it still runs ruff th cel says misfire on cylinder 4 plugs wires coils all
New within last 2 months help would be appreciated alot

 

I have the same problem with my 99 Ranger 4.0 except my misfire is on #2. I've spent a small fortune at auto shops and have so far replaced all spark plugs, plug wires and coil pack. No change. I am now told I need to pull the heads and have them rebuilt as it is probably a broken valve spring or bad valve seat. Because I have 171,000 miles on the engine the recommendation is to replace both heads with newly rebuilt ones. Needless to say this is going to be expensive as I can't do it myself. Anyway, research this possibility about the broken valve spring and you may find your answer. If you can do the work yourself you may get by with just replacing the valve spring if the seat is not ruined from the valve rattling around in it.

 

I found my Problem it was a cracked porcilean around the spark plug it runs like a champ now

 

Man, I'm happy for you. I assumed since you said you had all new plugs, wires, etc. that it was something else. They found a cracked spark plug on mine too (not on the cylinder misfiring) and I let them talk me into another all new set of plugs and wires. That didn't fix a thing and then I let them talk me into a new coil, still no change. The only thing I haven't thrown money at is a new fuel injector and I'm mulling over whether or not to go that one last step before I have the engine torn down. Anyway, I'm glad yours turned out to be something simple.
As a side note the mechanic who found the cracked spark plug said in all his years as a mechanic every cracked plug he'd ever run across was an Autolite. He said they are just more fragile when installing them, but he still uses them, he's just super careful putting them in. I don't know if this is true or not, but he had no reason to lie about it as he wasn't the one who installed the broken plug originally.

 

the plug that cracked was a ford motorcraft platinum oem plug but all in all i hope you find out what the problem was and if you do i would like to know what it was so i can have it for future problems like that but i recommend when you install them use some hose like vaccum hose so put it in and not mess up the gap or over tighten them

 

Torchranger,

Is your truck using any antifreeze at all? If your motor cracks the porcelain around the base of the plug again, I'd be willing to bet a cracked head is causing that. Keep that in the back of your head, as that happened to me. Just an FYI.

 

ranger dad i will keep that in mind but that is the first time its ever done that and it has 171,000 miles on it and its not leaking antifreeze that have seen

 

Sorry to piggyback on your post, but its a very similar problem. I noticed about a month ago my truck (98' ranger 4.0) starting using up some coolant, so i just kept refilling the reservoir thinking it was just a leak. Now just the other day all of a sudden it starts running really crappy, and gets a check engine light. Get it scanned, says Cylinder 4 misfire. Same thing as yours. My friend thought it may be a head gasket, or intake manifold gasket. Any other ideas for that combination of buring/leaking coolant and a Cylinder 4 misfire?

 

i made a typo it is leaking antifreeze aroung the timing cover but not enough to even notice but i check it and i hassnt really used any as for problems with misfire could be wires, plugs, coil, and probely alot of diffrent things

 

I have a 1998 4.0 OHV using coolant, started to misfire. Threw codes for coil pack and #4 cylinder. Changed Coil pack and coil pack connector. still throwing code for # 4. Did you ever fix yours? what was it?

 

Check your plug on 4. These engines are known to crack heads and burn just a touch of coolant. Try a pressure tester for the cooling system, you can borrow them from most auto parts stores for a deposit. It should be able to hold pressure if it doesn't you will need to track the escaping coolant down.