it's my birthday and my present from my explorer is....

...the engine started missing and idling rough. the check engine light has come on.

I have run fuel system cleaner thru it and a bottle of HEET and it hasn't helped.

i'm on my second bottle of heat with high octane gas now


trying to troubleshoot what could cause the problem. Any Ideas?

changed the fuel filter about 1.5 years ago
plugs are 1.5 years old

could it be the fuel pump?

thanks for any help and happy holidays

run to autozone if you have them in your area and they will pull the code up for you to give you an idea of where to start looking

Which Engine?

matt0248 said:

Which Engine?

Click to expand...

2002 4.6 v8

i'm headed up to advanced auto parts and going to get it checked for an error code per tmds3's advice

Check these out.....will take less than five minutes to rule in or out.

http://www.explorerforum.com/forums/showpost.php?p=1965554&postcount=11


http://www.explorerforum.com/forums/showpost.php?p=2345275&postcount=82

Update?

just got back from 2 autozones,

the reading was P0306 and it said "cylinder 6 misfire"

the young kid at the first autozone said it probably just needs a "tuneup"....which made me want to get another opinion

at the 2nd autozone, the guy told me it's probably a leak in the vacuum hose.

we briefly looked around for it but couldn't see/hear anything at a quick glance

He said it could be under the plastic cover on top of the engine.

does a vaccuum pressure leak sound like a possibility?

No, not really. It could possibley be a bad ignition coil. or plug. I beilive #6 is the second cylinder from the front on the drivers side. When was the last time plugs were changed? You can try moving #6 coil pack to a diffrent cylinder to see if the misfire follows the coil pack.

Generally on these engines a vacuum leak would not cuase a misfire on one specific cylinder. unless the leak was the intake manifold gasket leaking at that cylinder.

plugs were changed 1.5 years ago

will try moving the coil pack if i can, and see what I get back...never done it before

btw...any harm in driving it,

if i can't get this fixed right away, i'm gonna have to find some other wheels or santa's not going to show this year

posmindset said:

He said it could be under the plastic cover on top of the engine.

does a vaccuum pressure leak sound like a possibility?

Click to expand...

Did you read the two links I posted? The elbow is located under the cover. This is a common problem.

dont rule out a 1.5 year old plug unless u check it. i let a buddy change the plugs in mine cuz he needed money and i used to work with him so i trust him but 3 months later i had a misfire code and it turned out to be the ceramic around the electrode was cracked.

"On the first day of Christmas, my Explorer gave to me.....

A misfire on number 6 plug."

mine was mass air flow meter dirty.
clean it up and see,,,,,,,,,,,,,,,,,,,,,,,,, but i have oil K&N

Brought it to Dobbs, after running diagnostics, they believe it is one coil and plug however they are recommending replacing all the coils, plugs, wires, and sensors since they said when one goes bad it can affect the others too.

Does this sound correct or are they just inflating the work?

They quoted $1300 for everything.

Should I get another quote?

Thanks!

u could d it yoursef

posmindset said:

Brought it to Dobbs, after running diagnostics, they believe it is one coil and plug however they are recommending replacing all the coils, plugs, wires, and sensors since they said when one goes bad it can affect the others too.

Does this sound correct or are they just inflating the work?

They quoted $1300 for everything.

Should I get another quote?

Thanks!

Click to expand...

Run away - fast - they are trying to make tons on you.

As far as you know you have one cylinder misfiring - stay with that until proven otherwise (Occem's razor).

As was said, have the engine cover pulled, look for vacuum leaks - pretty easy really (but not the most likely cause of your problem but you might find a developing or hidden problem while in there), then pull #5 and #6 spark plug coil packs and swap them. If the problem is the coil pack the fault code will reappear and go to #5 cylinder (remember to clear the fault code after swapping coil packs so you can get a fresh readout on any future faults.

While in there I would also take a look at #5 and #6 spark plugs (for comparisons sake and to eliminate any potential plug faults). This is about one hour of labor or $60-100 max and no parts.

If you find that the #6 coil pack is bad, bingo you're done. Much cheaper.

One last question - what plugs did you install 1.5 years ago, factory specified originals or aftermarkets? Many have had big trouble with aftermarkets, including all those 'wonder' plugs (makes you wonder why folks use them)?

I think that your problem is cheap and easy - don't get taken to the cleaners on this one. Your problem may be as simple as the connector to the #6 coil pack is loose due to not being tightly reconnected when the plugs were changed last year.

Remember that an electrical fault code specific to a particular cylinder can only come from an electrical fault signal that comes from electrical items specific to one cylinder (only electrical items are the spark plug, spark plug coil pack, and fuel injector).

Let us know.

The guy that wants to charge you $1300 should be shot for felony extortion.

I 2nd the coil pack... Also, Jegs has coil pack kits for a ton less then that... I think the dealer has them for less too...

Swap the suspect coil pack with one of the other coil packs, say from #2. If the misfire moves to #2, then you know the coil pack is the culprit.

I had the exact same symptoms last year, and it turned out to be a failed injector. I did the same thing - swapped two injectors around, and the misfire moved to the cylinder that I moved the suspect injector to. A new injector and everything was fine again.

Run, do not walk away from the criminals trying to fleece you for $1300. One bad coil can't "affect all the others" much less the wires and sensors. They are doing "diagnosis by replacement" at your expense.

Rick I would like to discuss my XLT with you is that possible?
Pls. call 201.377.5981 Thanks in advance. Steve