Cylinder Misfire

[BlackMoses]

Hey guys,

Thanks for your help in advance.

I've got a 2001 3.0L V6.

I just pulled the codes after I got a check engine light a few days ago and it came up P0301, misfire in cylinder #1. I've had CEL's in the past, but they've gone away after about a week.

From everything I've read here and on the other Ranger forums it seems that the order to check this out is:

1.) Plugs
2.) Wires
3.) Ignition coil
4.) Injectors
5.) Valves

I changed the plugs and wires about a year ago, I've got Autolite Double Plats and JBA wires. I haven't changed my ignition coil, I'd like to test it first before I go buy a new one (not sure the proper method on the bench test, maybe you guys know). Not sure on the testing method for the injectors either, other then hooking up a multimeter and checking the resistance (what's the normal resistance suppose to be?). But, I do know for the valves I probably need to do a compression check and see whats up.

A little background on the truck is that she's got 89k miles on her, I've Seafoamed her about a year ago as well, and I did a pretty thorough job cleaning out the IAF and MAF when I did that. The idle has never really been as smooth as I like it, a little jerk here and there, but it's run pretty well so far.

Any suggestions!?

Thanks again!

 

[bcost882]

mmmm my truck doesn't like idling on balls hot air here in vegas but not so much it will misfire. that is the only code you have? and does it feel like it misfires all the time or just possibly a once in awhile thing? you can look at your #1 plug and see if it is fouled in anyway. those don't get gapped since they are double?? if they do regap em. compression check, otherwise might be the coil, not sure how to check either besides the inline spark module thing.

 

[James86]

Mine's always ran a little odd at idle, but not enough for check engine lights to come on. I know when my wife had a misfire on cylinder 2 in her passat, turned out the plug just happened to be bad. if nothing else, just plop a couple bucks on a plug and set the gap (if applicable) and see what unfolds.

 

[modelageek]

fuel filter. fuel pressure test

 

[RangerSVT]

Usually when you have a random noncontinuous misfire its time to change the plugs...If its been a year since your last tuneup (plugs), I'd go ahead and put a new set in, and if your wires have a warranty on them, I'd swap those out while your at it. Depending on the mileage you put on your truck, a year pretty decent. I get almost a year out of mine, which is on average around 20K or so...
SVT

 

[Big Jim M]

Holy mackerel Indian Mound! You actually put new plugs in every 20K? And here I am with 160K on mine. I doubt I even raise the hood every 20K. No wait, I do raise the hood to put more wiper fluid in the holding tank. Them plugs you take out, do you donate em to a poorer guy?
Big Jim

 

[RangerSVT]

Holy mackerel Indian Mound! You actually put new plugs in every 20K? And here I am with 160K on mine. I doubt I even raise the hood every 20K. No wait, I do raise the hood to put more wiper fluid in the holding tank. Them plugs you take out, do you donate em to a poorer guy?
Big Jim

No, I put very hard miles on my truck, and if you don't know Autolite DP's have a 50K warranty on them, so it doesn't cost me for another set...I can get about 35 to 40 out of a set, then I start getting random misfires, once every 2 weeks or so, but it irritates me so I change em out, especially since I don't have to pay for em...
SVT

 

[BlackMoses]

Thanks guys for the input, I'll give this stuff a shot this weekend and let you know how it goes.

Strangely enough my check engine light went off again, I'll also have to hook up the code reader and see if it's still in the system.