Reply
Fri 7 Dec, 2007 11:09 am
I have a 2000 mustang V6 with about 160,000 miles. a misfire cylinder 1 trouble code has been on and off for about a year and each time i replace ther spark plug and wire and it goes away. but for about 2 months it has been on and i tried replacing the spark plug and wire and nothing has happened. I've traken it to shops and they are confused. good fuel pressure test, replaced coil pack, wires, spark plugs, good air pressure test. good compression test actually it was pretty high. any suggestions or advice?
Is it truly missing, or just throwing a code...
RH
yea its truly missing. the engine shakes and you can feel it in the car.
I will be of limited help from here.
I would concentrate on the electrical end first, as previously that has solved it, and you've run compression.
Are you using a premium spark plug, and how does it look (the old plug) when you pull it after it has run while missing a bit (color, deposits, etc)
RH
yea its a premium spark plug but the spark plug does get a black substance on there like its burnt ot something. no smell of gas though
Does the car smoke at initial start up after it has sat for a day or so...
Is it (the old plug) dry black or wet black...
RH
dry black but no smoke at all
Again, I am far away, so use discretion.
I would look into a fuel problem in that cylinder. (injector, inj. seal) something is fuel fouling that plug....
RH
theyve checked the fuel injector by switching it with cylinder 2 and its still cylinder 1 misfire. fuel pressure test was good. one man told me it was fuel pump but others have told me for sure thats not it. cuz it would effect all cylinders not just 1.
Switching injectors does not rule out injector seal....
Are you working on this, or paying for guesses....
RH
i have a friend that is mechanic and hes doin it on his days off. i help a little but mostly him. i was told that the fuel injector was firing fine. the only guesses he had were floating valve and maybe something with the intake manifold.
No wish to supercede your friend, as he has hands on abitlity, so we will discuss theory...
Dry black is carbon build up due to a rich condition...
Excessive fuel is only possible thru a finite number of causes...
(your friend is following this same hypothesis)
I am not fully late Ford familiar, as these are things I opted to refrain from, but examine the system (injector o-rings first) to see what else would cause extra fuel in that hole.
The intake does not fit this, in my view...
RH
what about the floating valve idea? do u think this could be a possibility? he said that if it was o-ring related the compression test wouldve showed weak compression?
Floating valve usually happens due to a weak spring, and not at idle speeds. It is an upper RPM range occurance. I sticking valve could do it, but should show up on compression tests.
I will have to consult info not available to me on the weekends, but the O-ring I am looking for is fuel distribution related, and would leak almost zero compression.
RH
Outside of all that has been discussed, and strictly looking at the electrical perspective, one consideration that may be of benefit is to use a duel platinum (or iridium) plug because the polarity of the current through the spark gap can cause problems on single rare metal plugs.
Yer thinkin too hard, Chum.
The plug is carbon fouled, and it ain't causin' it itself...
No lightning around me, but I knows spark plugs... :wink:
RH
Rockhead wrote:Dry black is carbon build up due to a rich condition...
Or possibly from too cool a plug range not to say that is the issue here sight unseen.
160,000 mile ford v-6........
First of many troubles, none of which are high tech...
RH
Rockhead wrote:Yer thinkin too hard, Chum.
The plug is carbon fouled, and it ain't causin' it itself...
No lightning around me, but I knows spark plugs... :wink:
RH
I am not think too hard my V6 in my van works best with polarity specific plugs if you do not go dual.
You REALLY don't want to pick this with me Chum, but OK....
What is your van, and how many miles are on said (non-ford) vehicle????
RH
Stumble It!
Tweet This
Bookmark on Delicious
Share on Facebook
Share on MySpace