spark plug question

jim beam > wrote in :

> On 05/15/2012 04:45 PM, Ashton Crusher wrote:
>> On Tue, 15 May 2012 18:18:58 -0500, Jim >
>> wrote:
>>
>>> Ashton > wrote in
>>> :
>>>
>>>> On Mon, 14 May 2012 17:12:18 -0700, Ashton >
>>>> wrote:
>>>>
>>>>> I would appreciate any thoughts on what, if anything, these plugs
>>>>> are saying... lean, rich, too hot, too cold, whatever.
>>>>>
>
>>>>>
>>>>> http://img856.imageshack.us/img856/1732/imag01561.jpg
>>>>>
>
>>>>>
>>>>> they are from a 92 explorer with a low rpm miss. It scopes out
>>>>> fine yet misses. Replacing these plugs seems to "fix" it for
>>>>> about 5000 miles. Searching the net suggests the problem is that
>>>>> the fuel injectors are going bad and running too lean but not lean
>>>>> enough to set a code. No codes have popped up. Over 2000 rpm it
>>>>> runs smooth right up to redline in any gear.
>>>>
>>>>
>
>>>> Thanks for the replies. From the questions asked here is more info
>>>> to answer them and see if anyone has further thoughts.
>>>>
>
>>>> The engine runs like new power wise, other then this miss. It
>>>> doesn't burn any oil between changes or 3000 mile+. Only needs
>>>> more coolant perhaps once or twice a year, never blows white smoke
>>>> or any other smoke on startup. The shop that "fixed it" last year
>>>> said they could find no problems when I brought it in as it was
>>>> running fine that day. The ignition looked "fine" by whatever test
>>>> equipment they used. I brought it back two days later because it
>>>> started acting up again. This time they could occasionally
>>>> experience the problem while driving but could still find nothing
>>>> when they "tested" it. They did a fuel injector cleaning and gave
>>>> it back to me. It ran the same with the occasional miss. I
>>>> brought it back. At this point it had some bosch double plats in
>>>> it that I had put in about 5K earlier. The mechanic didn't like
>>>> the bosch plugs and said he thought it was the plugs even though
>>>> they "tested" OK. So I told him to go ahead and put whatever
>>>> plugs he liked in it which as Motorcraft copper core. When it got
>>>> it back it ran fine and continued to run fine until recently when
>>>> it started the same miss again.
>>>>
>
>>>> Here's a more complete description of the "miss". Sometimes it
>>>> will idle ok but when you start up you can feel a miss that feels
>>>> like a single cylinder. That may persist till you get it up to
>>>> about 2000 rpm and then it goes away. On the freeway it's fine,
>>>> kick it into passing gear and it's fine. Sometimes it will have
>>>> what feels like the single cylinder miss but as you accelerate
>>>> normally, say from a stop light, it gets to 1200 rpm and feels like
>>>> all of a sudden 2 or 3 cylinders are missing and it losses power
>>>> significantly. This may last for a few seconds and then it clears
>>>> up and goes back to a single cyl type miss and then goes away. I
>>>> thought it was ignition till I read the below...I'm on the road now
>>>> so I'm just hopping three new plugs will eliminate the problem for
>>>> a few weeks.
>>>>
>
>>>>
>>>> From the net....
>>>>
>
>>>> I had the same problem with my '95. Low RPM miss I couldn't track
>>>> down. Did all the usual checks/replacements of vacuum leaks, plugs,
>>>> wires, coil pack, sensors, etc... Then I decided to check the
>>>> resistance I was getting off of my injectors after none of that
>>>> resulted in the miss getting fixed. BINGO! even though I wasn't
>>>> getting a CEL, the truck was running lean, but not lean enough to
>>>> throw a code. I had 2 bad injectors, and another 2 reading higher
>>>> than normal. Normal range is between 13 and 19 Ohms. One was way
>>>> off intermittently at 54 Ohms, and another was just over 24. the
>>>> other 2 were just about 21 Ohms, definitely out of spec.
>>>>
>>>> So I ordered a new set of 6 ( what is the point of just replacing
>>>> the ones that were bad, seeing the others could go at any time as
>>>> well) from a place online. $120 for all 6 shipped, can't beat that
>>>> deal anywhere! And they are FORD parts.
>>>>
>>>> Anyway's, after getting them all installed (about 2 hours of work
>>>> total) The miss was gone and has been running like it was brand new
>>>> ever since.
>>>>
>
>>>>
>>>>
>>>> I was ready to start throwing parts at it
>>>>
>>>
>>> have you replaced your plug WIRES? distributor cap/rotor?
>>> the wires do get old and begin to break down. Then your plugs will
>>> misfire.
>>
>>
>> Wires are only a couple years old. Took it out for a drive tonight
>> with the three new plugs in it and it purred like a kitten, not a
>> single miss. When I get home I'm going to pull one of the plugs on
>> the other side and see what that side looks like but it seems that
>> side is OK.
>
> fine, but just like jim is saying, don't dismiss the wires/cap being
> dodgy. they may be making connection now because you've just
> manipulated them fitting the new plugs, but it doesn't mean they're
> 100% good. just like being only 2 years old doesn't mean they're
> good.
>
>

constant pulling of the plug wires can damage the center
conductor/connection,usually at the ends.
or there could be an insulation break,allowing your spark energy to go
astray,under certain conditions.

Or a cheapo dist.cap/rotor could cause problems.

--
Jim Yanik
jyanik
at
localnet
dot com

On 05/16/2012 07:58 AM, Jim Yanik wrote:
<brevity>
>>
>
> constant pulling of the plug wires can damage the center
> conductor/connection,usually at the ends.
> or there could be an insulation break,allowing your spark energy to go
> astray,under certain conditions.

indeed.

>
> Or a cheapo dist.cap/rotor could cause problems.

yup. but if it's a rotor, it's usually a problem affecting all
cylinders, not just one.


--
nomina rutrum rutrum

On Wed, 16 May 2012 19:16:27 -0700, jim beam > wrote:

>On 05/16/2012 07:58 AM, Jim Yanik wrote:
><brevity>
>>>
>>
>> constant pulling of the plug wires can damage the center
>> conductor/connection,usually at the ends.
>> or there could be an insulation break,allowing your spark energy to go
>> astray,under certain conditions.
>
>indeed.
>
>>
>> Or a cheapo dist.cap/rotor could cause problems.
>
>yup. but if it's a rotor, it's usually a problem affecting all
>cylinders, not just one.


On this Vehicle, the explorer, there is no distributor, just a
computer and coil pack and pickup coil down by the harmonic balancer.
One of the reasons I'm leaning toward the fuel injectors as the
underlying problem is that in the past when I've had ignition system
problems they were the worst at high load/high rpm. In this case the
problem goes away at high load-high rpm. I wonder if what I'm
perceiving as a "Miss" is really knocking from too lean a mixture.

On May 17, 12:15*am, Ashton Crusher > wrote:
> On Wed, 16 May 2012 19:16:27 -0700, jim beam > wrote:
> >On 05/16/2012 07:58 AM, Jim Yanik wrote:
> ><brevity>
>
> >> constant pulling of the plug wires can damage the center
> >> conductor/connection,usually at the ends.
> >> or there could be an insulation break,allowing your spark energy to go
> >> astray,under certain conditions.
>
> >indeed.
>
> >> Or a cheapo dist.cap/rotor could cause problems.
>
> >yup. *but if it's a rotor, it's usually a problem affecting all
> >cylinders, not just one.
>
> On this Vehicle, the explorer, there is no distributor, just a
> computer and coil pack and pickup coil down by the harmonic balancer.
> One of the reasons I'm leaning toward the fuel injectors as the
> underlying problem is that in the past when I've had ignition system
> problems they were the worst at high load/high rpm. *In this case the
> problem goes away at high load-high rpm. *I wonder if what I'm
> perceiving as a "Miss" is really knocking from too lean a mixture.- Hide quoted text -
>
> - Show quoted text -

I'd replace the wires first. That is your next weakest point. Since
you moved the wires your problem has stopped for the time being. I'm
having the same issue w/ my car and I'm gonna replace the wires next.

Ashton Crusher > wrote in
:

> On Wed, 16 May 2012 19:16:27 -0700, jim beam > wrote:
>
>>On 05/16/2012 07:58 AM, Jim Yanik wrote:
>><brevity>
>>>>
>>>
>>> constant pulling of the plug wires can damage the center
>>> conductor/connection,usually at the ends.
>>> or there could be an insulation break,allowing your spark energy to go
>>> astray,under certain conditions.
>>
>>indeed.
>>
>>>
>>> Or a cheapo dist.cap/rotor could cause problems.
>>
>>yup. but if it's a rotor, it's usually a problem affecting all
>>cylinders, not just one.
>
>
> On this Vehicle, the explorer, there is no distributor, just a
> computer and coil pack and pickup coil down by the harmonic balancer.
> One of the reasons I'm leaning toward the fuel injectors as the
> underlying problem is that in the past when I've had ignition system
> problems they were the worst at high load/high rpm. In this case the
> problem goes away at high load-high rpm. I wonder if what I'm
> perceiving as a "Miss" is really knocking from too lean a mixture.
>

any codes in the ECU? there are codes for coil pack malfunctions.


--
Jim Yanik
jyanik
at
localnet
dot com

In message > , Jim Yanik
> writes
>Ashton Crusher > wrote in
:
>> On Wed, 16 May 2012 19:16:27 -0700, jim beam > wrote:
>>>On 05/16/2012 07:58 AM, Jim Yanik wrote:
>>><brevity>
>>>> constant pulling of the plug wires can damage the center
>>>> conductor/connection,usually at the ends.
>>>> or there could be an insulation break,allowing your spark energy to go
>>>> astray,under certain conditions.
>>>indeed.
>>>> Or a cheapo dist.cap/rotor could cause problems.
>>>yup. but if it's a rotor, it's usually a problem affecting all
>>>cylinders, not just one.
>> On this Vehicle, the explorer, there is no distributor, just a
>> computer and coil pack and pickup coil down by the harmonic balancer.
>> One of the reasons I'm leaning toward the fuel injectors as the
>> underlying problem is that in the past when I've had ignition system
>> problems they were the worst at high load/high rpm. In this case the
>> problem goes away at high load-high rpm. I wonder if what I'm
>> perceiving as a "Miss" is really knocking from too lean a mixture.
>any codes in the ECU? there are codes for coil pack malfunctions.
I know it's considered out of date and very seldom practised nowadays,
but "Pinking" or pre-ignition can sometimes be caused by a build up of
carbon near the plug in the head which glows red hot as the engine gets
warm. A good 100mile blast as hard as you can down a motorway normally
burns that off. The usual reason for carbon buildup is if the engine
is under utilised, to lightly loaded or never given for more than a few
mile as a time.
--
Clive

"Clive" > wrote in message

> I know it's considered out of date and very seldom practised nowadays, but
> "Pinking" or pre-ignition can sometimes be caused by a build up of carbon
> near the plug in the head which glows red hot as the engine gets warm. A
> good 100mile blast as hard as you can down a motorway normally burns that
> off. The usual reason for carbon buildup is if the engine is under
> utilised, to lightly loaded or never given for more than a few mile as a
> time.
> --

These plugs dont seem to have carbon on the electrode areas. They have a
white slag of mineral deposits, it would appear. There is also a little
red
color to some of these, which could be iron/rust.

Nontheless, these deposits can cause the pinging you describe in the same
way as carbon deposits.

But where is this coming from? If antifreeze were bleeding into the
cylinders,
it might give this sort of scale product. Some kinds of oil additives might
also burn off white like these deposits.

5000 miles is too short a time to use up a set of plugs traditionally.
Something
here doesnt quite fit.

On May 14, 8:12*pm, Ashton Crusher > wrote:
> I would appreciate any thoughts on what, if anything, these plugs are
> saying... lean, rich, too hot, too cold, whatever.
>
> http://img856.imageshack.us/img856/1732/imag01561.jpg
>
> they are from a 92 explorer with a low rpm miss. *It scopes out fine
> yet misses. *Replacing these plugs seems to "fix" it for about 5000
> miles. *Searching the net suggests the problem is that the fuel
> injectors are going bad and running too lean but not lean enough to
> set a code. *No codes have popped up. *Over 2000 rpm it runs smooth
> right up to redline in any gear.

What was the Bosch part # installed? Maybe the wrong plugs are
installed as well?

On Thu, 17 May 2012 11:53:56 -0700 (PDT), m6onz5a
> wrote:

>On May 14, 8:12Â*pm, Ashton Crusher > wrote:
>> I would appreciate any thoughts on what, if anything, these plugs are
>> saying... lean, rich, too hot, too cold, whatever.
>>
>> http://img856.imageshack.us/img856/1732/imag01561.jpg
>>
>> they are from a 92 explorer with a low rpm miss. Â*It scopes out fine
>> yet misses. Â*Replacing these plugs seems to "fix" it for about 5000
>> miles. Â*Searching the net suggests the problem is that the fuel
>> injectors are going bad and running too lean but not lean enough to
>> set a code. Â*No codes have popped up. Â*Over 2000 rpm it runs smooth
>> right up to redline in any gear.
>
>What was the Bosch part # installed? Maybe the wrong plugs are
>installed as well?

I just started here, so excuse me if this was covered.
Good point about which plug. In my experience OEM is best.
Those plugs look oil fouled. Not bad though, and it's running good
enough to burn off most the oil.
Could be blowby, could be valve seals.
For valves seals oil gets sucked in at higher vacuum, backing down on
speed or idling.
I had a Ford 352 that would use a quart every 500 miles in local
driving. Went on a 3000 road trip and didn't use a quart.
****ed me of because I had completely rebuilt it, but the shop I took
the heads to screwed up on the valve seals.

Without the miss the plugs may stay clean. Maybe.
You don't mention miles on the engine.
I've never had luck pinpointing bad injectors. Just did OHM tests
though. Always bit the bullet and put all new in.
'92 is getting long in the tooth. You might want to run a compression
test before you throw money at it.

--
Vic

In message
>,
m6onz5a > writes
>On May 14, 8:12*pm, Ashton Crusher > wrote:
>> I would appreciate any thoughts on what, if anything, these plugs are
>> saying... lean, rich, too hot, too cold, whatever.
>> http://img856.imageshack.us/img856/1732/imag01561.jpg
>> they are from a 92 explorer with a low rpm miss. *It scopes out fine
>> yet misses. *Replacing these plugs seems to "fix" it for about 5000
>> miles. *Searching the net suggests the problem is that the fuel
>> injectors are going bad and running too lean but not lean enough to
>> set a code. *No codes have popped up. *Over 2000 rpm it runs smooth
>> right up to redline in any gear.
>What was the Bosch part # installed? Maybe the wrong plugs are
>installed as well?
I've just had a quick look, the left one looks to be OK the right two
definitely look like lean mixture to me.
--
Clive