running like crap

[snomaker321]

my truck is running like crap. Sometimes itll be fine but then itll start shaking like crazy. i got the codes pulled and it was a misfire on cylinder 2. I changed all the plugs since they had 128000 miles on them but it did absolutely nothing. Not sure if i should just get new wires etc or if something more serious could be going on here. should also mention that usually when it starts running really bad the cel will flash, which i know is not good at all. any help greatly appreciated.

 

[Big Jim M]

Start with new wires. Change them out ONE AT A TIME! Thataway you won't get them mixed up.
Big JIm

 

[Ranger44]

Yeah, when I do a tune-up I replace everything.

As for the miss fire.....could be a leaky plug wire, or one with high resistance.

Don't rule out the fuel system either. Could not be getting fuel.

Eliminate the ignition system. Verify each plug wire has spark. Get you a spark tester.

Then go to your fuel system. Check fuel pressure at the rail. If that's good. Get ahold of a stethoscope or noid light and check the injectors. Make sure they are getting signal and pumping fuel.

Check back later with your results.

 

[snomaker321]

ok so i think i know how to check the wires, but as for the fuel system i have no idea. any links to a how to?

and for wires, stick with motorcraft? or is there something better out there.

the biggest thing im worried about is my cel flashing. i gotta figure this out.

im really shocked that changing the plugs did nothing. i mean like these were the original plugs and there was barely anything left to them, but after changing them nothing changed. its pretty disappointing


thanks for all the help guys. hopefully ill get to some testing after school tomorrow

 

[Runnin'OnEmpty]

ok so i think i know how to check the wires, but as for the fuel system i have no idea. any links to a how to?

and for wires, stick with motorcraft? or is there something better out there.

the biggest thing im worried about is my cel flashing. i gotta figure this out.

im really shocked that changing the plugs did nothing. i mean like these were the original plugs and there was barely anything left to them, but after changing them nothing changed. its pretty disappointing


thanks for all the help guys. hopefully ill get to some testing after school tomorrow

I'd read the codes again, and verify it's still missing
on #2 cyl. This might be an upper plenum gasket leak.....

 

[snomaker321]

well this isnt the first time ive had the cel come on for misfire on cylinder 2, and it was acting the same way when i least pulled the codes about a week ago, but i will go to the store next chance i get to make sure.

 

[snomaker321]

i just checked the resistance on the cylinder 2 wire and got 6000 ohms. I thought these were supposed to be between 10k-15k per foot. i didnt take the wire all the way off(couldnt figure out how to work the clips) but its def at least a foot.
I did cylinder 1 and it came in at 10,000 ohms

i should also add that this seems to happen at the same place every morning. Its about 2 miles from my house and usually the truck has been running for about 10 min by then. its all up hill there. i usually get to a red light and the truck will just start shaking and the cel will flash. this is really the only time ive noticed it happen and it doesnt happen on my way home from school

 

[Lonewolf]

plug wires do some strange things when they get old, get oil on them, or just get dirty
sometimes you can see the spark jump if it is real dark when you rev it to a certain rpm
plugs are not as critical as the wires, they usually jump the spark there anyway
IMO