Differently worn spark plug electrodes. Wires or coil pack?

[FloridaGrown]

I've got a 4.0 2000 ford ranger. I changed my fuel filter and plugs. I found two of the six spark plug electrodes where more worn then the others. I'm assuming this means there's a weak spark going to four of the cylinders and a hot spark going to two. Or visa versa. My truck also lacks power. Do these plugs look gapped correctly? It's too big right? Also, the truck has a small unpredictable random rare jerk that lasts a second. No CEL. I'm guessing it's the coil pack missing on two cylinders and it causes the truck to jerk because of it's unbalanced crankshaft when it has no spark. I'm also purchasing a fuel pressure tester tomorrow. Does anyone know the pressure the motors supposed to be at when running and idle? Also, when the motors cut off? Thanks, Let me know what you think. Aaron.

 

[kunar]

What cylinders were the plugs in question?
Also, why is this in the 2.8 forum? Lemme see if I can move it from Tapatalk...

 

[FloridaGrown]

What cylinders were the plugs in question?
Also, why is this in the 2.8 forum? Lemme see if I can move it from Tapatalk...

Whoops sorry. wrong button.

 

[FloridaGrown]

I don't know know I didn't mark them. I didn't notice this until all the plugs where out. I know. Dumb*** mistake. Are you suspecting a blown head, worn valve seat? I'm not loosing coolant. The plugs aren't showing signs of burning oil. I can do a leak down and compression test. I don't think the heads blown. It runs to well for a blown head. I could run dye through the engine but I don't think it's a compression issue. If that's what your suspecting. Let me know what you think. The truck also has a vibration. Like a small miss. no one notices it but me.

 

[kunar]

Nope, I was wondering if its in the coil pack actually. The way that those are built, theyre really 3 separate coils. Each time one fires, its actually firing both plugs on that coil. The spark leaves the coil, goes through one plug, through the block, through the opposite plug and back to the coil. So, 3 of the plugs fire from electrode to ground, the other 3 fire from ground to electrode. I honestly wouldn't stress it too much. If you're really worried, pull the plugs in a thousand miles and check em again. Keep track of where they come from this time.

 

[FloridaGrown]

I'm OCD to the max. So that's it? You can't tell where the plugs come from so Your not interested? Alright I'll let people know that are interested.

 

[BRUTUS_T_HOG]

The gap is way too big. Put double platinum plugs back in it and re-test. 3 of the plugs fire from ground to center electrode and the other 3 fire from center electrode to ground. The plugs wear differently depending which way they fire. Double platinum plugs resist wear from bth directions.

Highly recommend new wires also, they tend to get minute damage when removed an become a problem down the road.

 

[kimcrwbr1]

It just looks like it has been a long time since the plugs were changed last. Put in new plugs, wires, PCV and then do a decarb on the engine. Get a can of seafoam and bring it up to normal temp and draw 1/2 a can of sefoam into the brake booster hose at around 2000 rpms and quickly shut it down. Wait half an hour and the start and run it around 3000 rpms until the smoke clears. Preventive maintenance first and then diagnose if necessary. What does the oil look like?

 

[FloridaGrown]

just replaced the Coil pack. Idles smoother then ever. It was the coil pack. I'm going to change my wires also.