spark plug question

On 05/23/2012 08:59 AM, Scott Dorsey wrote:
> In >, jim > wrote:
>> On 05/22/2012 07:16 AM, Scott Dorsey wrote:
>>> In >, jim > wrote:
>>>>>
>>>>> I, and a lot of other folks, have had trouble with the expensive Bosch
>>>>> plugs. The inexpensive Silber plugs, though, are just fine and are the
>>>>> plugs of choice in air-cooled VWs and older BMWs.
>>>>
>>>> i know a lot of people do that, but i can't see the point taking the
>>>> chance. or to put it another way, have you or anyone you know ever had
>>>> a problem with ngk in those applications?
>>>
>>> I have. The NGKs don't work well at all in the BMW M30.
>>
>> interesting. did you experiment with the heat range at all? i know
>> some of the more modern bmw's come with custom 4-ground ngk's from
>> factory so i can't imagine what any disruption mechanism might be other
>> than mistaken spec.
>
> I did not, although since I just ordered a set of Silbers for the 2002
> and Bavarian Motorsport charged me $6 each for the things, maybe I will in
> fact play with slightly hotter and cooler NGKs next time. The Silbers are
> the plugs that are well under a Euro in Germany....
> --scott
>
>

if you're paying that kind of money, go for the ngk iridiums [but shop
around - prices vary a lot]. very wide heat range, and the fine
electrode will fire almost any extreme of mixture.


--
nomina rutrum rutrum

On Mon, 14 May 2012 17:12:18 -0700, 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.


Update on this.... Got home so it's 4000 miles later. In the first
50 miles of the return trip it started missing again and I almost
turned back. It was raining most of that 50 miles. Slogged on
another 10 miles to the Interstate Service Area with it seeming to
come and go. Check engine light flashed on and off and on and off
several times and then stayed on. Got to the Service area and shut it
off, opened the hood and poked around looking for wetness but
everything seemed dry. Started it back up and the light was off and
it ran fine. Ran fine for the rest of the trip, 4000 miles. Yesterday
I drove it quite a bit and no problems and when I got home I left it
on and got my infrared heat measuring gun and measured the exhaust
manifold by the three cylinders on the side I replaced the plugs.
Front cyl was about 450 degrees, second cyl 550 and third cyl 550. So
that's making me think it may be related to those fuel injectors
running too lean as was suggested by the web post I found. Anyone know
what the "normal" temp is when getting a manifold temp reading like
this?? Averaged 20.5 mpg for the trip.

On 06/22/2012 04:09 PM, Ashton Crusher wrote:
> 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.
>
>
> Update on this.... Got home so it's 4000 miles later. In the first
> 50 miles of the return trip it started missing again and I almost
> turned back. It was raining most of that 50 miles.

if you can't connect rain with an indication of an issue with the
ignition system, then the problem is in the passenger compartment, not
the engine compartment.


> Slogged on
> another 10 miles to the Interstate Service Area with it seeming to
> come and go. Check engine light flashed on and off and on and off
> several times and then stayed on.

but you didn't bother to pull the code, just like you can't be bothered
to report what it is...


> Got to the Service area and shut it
> off, opened the hood and poked around looking for wetness but
> everything seemed dry.

of course - humidity is always irrelevant if something's not actually
soaking wet.


> Started it back up and the light was off and
> it ran fine.

after the warmth of the engine had dried it out...


> Ran fine for the rest of the trip, 4000 miles. Yesterday
> I drove it quite a bit and no problems and when I got home I left it
> on and got my infrared heat measuring gun and measured the exhaust
> manifold by the three cylinders on the side I replaced the plugs.
> Front cyl was about 450 degrees, second cyl 550 and third cyl 550. So
> that's making me think it may be related to those fuel injectors
> running too lean as was suggested by the web post I found.

and ignoring all the other usenet posts that disagree...


> Anyone know
> what the "normal" temp is when getting a manifold temp reading like
> this?? Averaged 20.5 mpg for the trip.

it's not the temperature, it's the /difference/ in temperature.


bottom line, if you want to go ahead and change the injectors, then go
ahead and do it. just don't keep bothering us about it - especially
since you don't want to analyze what these symptoms indicate, and you're
clearly not prepared to listen to anyone else who does.


--
fact check required