"cyl 3 misfire"

[boominXplorer]

check the wirering on the actual plug wires. Also pull plug 3 off the coil when running but keep it close to the pack so you can see if there is current running though (do this at your own risk of shocking yourself)

 

[mikeh]

Put an inline spark tester on plug 3 and see if it is consistently getting spark. Also do a compression test and let us know the results.

mikeh

 

[2001ExpSport]

2001ExpSport, does the engine run OK until it warms up, or just for a short time after starting? Brain, Goliath, are you still there?

It runs fine during the "choke" period.

After talking with a few of my car mech friends, they are leaning towards a clogged injector.

 

[2001ExpSport]

check the wirering on the actual plug wires. Also pull plug 3 off the coil when running but keep it close to the pack so you can see if there is current running though (do this at your own risk of shocking yourself)

I did that....and...I shocked myself...thanks jerk...........LOL...actually I did that when I was checking the coil on Sunday. It sparks just fine.

 

[2001ExpSport]

Put an inline spark tester on plug 3 and see if it is consistently getting spark. Also do a compression test and let us know the results.

mikeh

Time is tight since everyone has deadlines except me...lol. I will be doing all these tasks this weekend.

I will be sure to keep everyone updated.

Thanks for the great help guys.

Matt

 

[Brain]

Still here (just a lot of distractions). The OBDII computers aren't actually that dumb as they can compensate for quite a few things, but they can't fix (compensate for) things once they go too far out of whack. They can tell which cylinder isn't pulling its weight by taking readings from the crank position sensor (less acceleration between two points). If it was a spark problem, I don't think the problem would only happen when it's warm, I would think that it would happen all the time. The computer also has a different code for spark failure. Same thing with compression...what would make compression good when it's cold and bad when it's warm? It still sounds like a fuel injector issue to me, but like I said before, the easy things should be ruled out first.

 

[2001ExpSport]

Update

OK...well...I haven't tested compression yet because I am leaning away from it being a mechanical issue. ONly because it it were mechanical it would be constant. I will get to it this weekend.

On to the fun...

I plopped the coil back in and started it up today to move the thruck and #3 didn't fire at all. Now like I said before, it ran ok during the "choke" period but studders after that. This time it ran bad right from the start. Here's the kicker, once it warmed up #3 mysteriously began firing and did so the rest of the drive. At my destination I shut it off and restarted it, still hot, #3 wouldnt fire. I took it back out and after about 2 minutes #3 fired normally again. Shut it off, started it up....#3 won't fire. After a minute or so it fires.

The thing is, when it's hot, it runs like a bat out of hell and better since the plug and wire change. Oh and btw, all the old plugs were in excellent condition and identical in color.

I'm putting my money on fuel starvation due to a clogged/bad injector?

What are the odds of a fuel injector failing this early?

Comments?

 

[Critical_Level2]

One idea is to switch the injector to a different cylinder, then if that cylinder starts misfiring then that is the problem, if it makes no difference then it is not the injector. It may seem like a little more work, but it would save you from buying a new injector if that is not the problem.

 

[captTelescope]

Duh! (whacking myself upside the forehead). Same deal with the coil packs. Switch 'em around & see what happens. A bad coil isn't ruled out yet, in my mind. Easier than an injector swap?

Attaboy, CL2!

 

[2001ExpSport]

Verdict

Clogged injector on #3...

Everyones help was greatly appreciated!

 

[CHEVELLE]

Hello, I'm having similar problems with my explorer. Cyl 8 misfire. It has 40,000 miles on it changed spark plug no difference. Is it possible to clean an injector? Or must it be replaced? What did you do with yours? Anyone use those bottle of injector cleaners that you add to your fuel? I've been hesitant to use them because of fear they could do more harm then good. Thanks!

 

[2001ExpSport]

Hello, I'm having similar problems with my explorer. Cyl 8 misfire. It has 40,000 miles on it changed spark plug no difference. Is it possible to clean an injector? Or must it be replaced? What did you do with yours? Anyone use those bottle of injector cleaners that you add to your fuel? I've been hesitant to use them because of fear they could do more harm then good. Thanks!

My mechanic sold me a injector cleaner you can't get at Pep Boys or others. Gumout and cleaners like that won't work.

Blaster FIC

It fixed my problem after half a tank, but you'll need to run two 3/4 tanks.

My mechanics instructions were to add the full tank amount to 3/4 of a tank.

Good luck,
Matt

 

[CHEVELLE]

Thanks Matt. My problem is very similiar to yours so I'm going to give some injector cleaner a shot. Just found this website, it's cool and very heplful. Thanks for the advice.

 

[Raminator157]

Matt

I have the same problem exactly. Cylinder 3 misfire. I replaced the IAC. I did use one thing of fuel injector. That was it. Should I dump like 3 bottles in at once? Or should I go after the plugs? The plugs are stock from Ford and have not been changed yet. They have almost 50,000 miles on them

 

[2001ExpSport]

Hey, well my problem went away long ago. I had Ford replace the intake o-rings. After that I replaced the IAC valve and fuel filter.

I used a few bottles of injector cleaner as well, but it still would rear it's head occasionally.

At my regular oil change place they had a special on the fuel injection cleaning system and I had them do that last year. Since then I've had no re-occurance of the problem.

 

[BIGTREAD]

can injector cleaner cause damage??

I'm chasing a similar problem on another thread here and belive clogged injector on #3 is the problem. I dumped a bottle of cleaner in with 1/4 tank and drove around for half and hour. Then I topped the tank off and drove around for another fifteen or twenty mintues. Wanted to concentrate the stuff, but am worried that it could cause damage if over used like this. Anyone know?

By the way, each time I get in the cold start is better, and it picks up cyl #3 more quickly. Now it takes idling over 2K RPM for about thirty seconds to clear. If it is just a clogged injector the problem should fade away soon enough.

 

[iammattchew]

Eh, it's going to burn!

I've got the same problem... well I have a CEL and an exhaust leak, but I don't really mind the drone of the exhaust leak, it's aft the O2 censors at least.

Going to try MORE Injector cleaner.