Picture of my bad jeep spark plugs - Off-Road Forums & Discussion Groups
Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ and JK

 
LinkBack Thread Tools Display Modes
post #1 of (permalink) Old 11-30-2000, 11:06 AM
**DONOTDELETE**
Guest
 
Posts: n/a
Picture of my bad jeep spark plugs

Put in a TR covertion , THANK YOU TR. Changed my plugs and found this. It is a 84 cj-8 258,t5,300,3:31 gears. Top plug came out of No. 5 .Middle plug out of No. 3. Middle plug has the porcelain in the center broke and slids up and down the electrode . These are champion plugs RFNI4LY I replaced them with AUTOLITE 985. I have timed this jeep and made sure it did not ping because we did pull a 1500 lb trailer 250 mi each way 2 times. Only pull in 4 th gear. did drive it home once with the header pipe off the manifold for 150 mi . I don't think that would do it. What do you think did this to the plugs

Attached Images
File Type: jpg 9-272829-Jeep-plugs_WEB.jpg (57.4 KB, 9 views)
Sponsored Links
Advertisement
 
post #2 of (permalink) Old 11-30-2000, 06:00 PM
Moderator
 
Dirt Dog's Avatar
 
Join Date: Nov 1999
Location: Troy, Ohio
Posts: 7,409
Thanks: 1
Thanked 0 Times in 0 Posts
 
Re: Picture of my bad jeep spark plugs

Man I can't believe those!!!!!!!
I don't have any answer but mine look great.
(we have about the same combo)
Try and e-mail TR

Lead , follow , or WINCH ME OUT!!!!
http://home1.gte.net/rythem/davescj7.htm
Dirt Dog is offline  
post #3 of (permalink) Old 11-30-2000, 06:50 PM
Veteran
 
Join Date: Nov 2000
Location: newly relocated to Huntsville, AL
Posts: 845
Thanks: 0
Thanked 0 Times in 0 Posts
 
Re: Picture of my bad jeep spark plugs

I had a car that would melt the ends off the plugs like that. Was told that this was caused by a cylinder running too lean, possibly a leak in the intake to that cylinder. you can check that by spraying carb cleaner around intake while idling and listen for rpm change......having said all that, with my car, i never found the leak.....sold it and bought a jeep! good luck


"Fear causes hesitation and hesitation causes your worst fears to come true"
80cj is offline  
Sponsored Links
Advertisement
 
post #4 of (permalink) Old 11-30-2000, 07:30 PM
**DONOTDELETE**
Guest
 
Posts: n/a
Re: Picture of my bad jeep spark plugs

I installed a set of the exact same plugs in my father in laws 84CJ7 with a 258 and as soon as we fired it up it had a noticeable miss. I would pull a plug wire and try to pin point the cylinder not firing. When I did find it and pulled that plug it had the insulator bouncing up and down just like your # 3 plug. These plugs had zero miles on them.

post #5 of (permalink) Old 11-30-2000, 08:37 PM
Keyboard Implanted
 
Join Date: Sep 1999
Location: Near Chicago, IL
Posts: 2,537
Thanks: 0
Thanked 1 Time in 1 Post
 
Re: Picture of my bad jeep spark plugs

I love buying plugs that were dropped before I buy them. They work o so good. They add 50 extra HP when they are cracked. So what if the motor dosen't run well.

Andytron is offline  
post #6 of (permalink) Old 11-30-2000, 10:43 PM
**DONOTDELETE**
Guest
 
Posts: n/a
Re: Picture of my bad jeep spark plugs

The RFN14LY are the right original plugs but has there been any engine work? The middle one (and possibly top) may have been crushed by the piston (?). If the Autolite 985 is a direct cross-referenced match of the same bottom length then pull them out and see if they are still okay.

post #7 of (permalink) Old 12-01-2000, 09:02 AM
 
Join Date: Sep 1999
Posts: 5,383
Thanks: 0
Thanked 1 Time in 1 Post
 
Re: Picture of my bad jeep spark plugs

The top plug was either Mechanical Damage, Or Detonation.
I'd say Mechanical Damage by the looks of it.

Over heat and detonation go hand in hand, and if you add in lugging the engine while towing, and cheap gas, it's a recipe for disaster.
You have to remember that the hard parts of that spark plug are probably imbedded in the top of your piston...

Lugging the engine while towing will cause both over heating if the spark plug electrodes, and detonation.
Running without an exhaust system will lean the system further, causing detonation and over heat problems.
Go back one or two heat ranges, use premium fuel when towing, and don't lug the engine when it knocks.
You may also try backing the timing off a couple or three degrees when you lug the engine.
(You can always kick the ignition back up when you are just going to be driving around with no extra load...)

The reason I say mechanical damage is because the porcelain is completely broken away.
If you use one of those little coins to gap your plugs by prying down on the center electrode, you stand a 50/50 chance of ruining the spark plug before it's even installed.
NEVER PRY ON THE CENTER ELECTRODE FOR ANY REASON!!
Get a pair of needle nose pliers and grab the ground electrode, and bend it away from the center electrode....
What you have is what is left after you crack the porcelain.
That is also what is left after one is detonated to death, so I can't be sure...
--------------------------------------

The bottom plug is TOO HOT! ------WAY- WAY!! TOO HOT!
You have a much 'hotter' ignition now, so you can sneak back one or two heat ranges.
See how long the porcelain 'Neck' is on your plugs compared to normal modern plugs?
That long neck is to keep the heat in the tip, and burn away deposits.
If the neck was shorter, it would pass the heat to the body of the plug, and too the head for dissipation by the cooling system.
---------------------------------

The ignition is updated to the '90's, so maybe you should use a plug with the same heat range of say, an '92 or '93 or so Ford truck, and see if that helps...
SAME HEAT RANGE, NOT THE SAME PLUGS...
Plug reach should be considered here, and I just haven't done any research on the differences in plug reach or threading, or the taper or gasket method of sealing.

Ask the guy what heat range the stock 302 V-8 or 300 I-6 uses in say, a '92 truck.
Then order that same heat range in a plug for your Jeep...
---------------------------------

Believe this or not, a vacuum gauge will tell you if a plug (or plug wire or cap and rotor problem) is doing something stupid....
Did any more of the plugs show signs of taking a beating or over heating?
Are you keeping a CLOSE check on the new plugs?
---------------------------------

We usually find at least 1 out of a set of 8 plugs to be defective right out of the box.
Autolite is about 1 out of 10 or 12, but still, it's a pretty bad statistic.
I do wish they would put a little plastic protective collar on the end of the plug before shipment, (like at least one Jap company does).

If you have a Haynes Manual or Motor Manual, look in the back, there should be a set of pictures that shows you some of the different problems, and what causes them.
----------------------------------

This is one of those problems where there are usually several contributing factors that manifest into one large problem.
Don't kick yourself over this one. It's usually unforeseeable, and it's very fixable.

Better gas, very SLIGHTLY richer fuel mixture (if it's the fuel mixture, you are right on the edge of the perfect ratio, so very small changes go a long way!!), decreased timing advance, cooler plugs, and sometimes better spark plugs (I hate Champion.... Personal opinion there....) and maybe even some better plug wires will all help stop the problem...

If you are having problems with your wife, tell here this is a good reason to go with fuel injection!!!! See if she will work overtime to help pay for it!!!
(Just though I'd try!...)

If you still have problems, e-mail me, and we will go over the finer points of how to track this down.... [email protected]

See Ya, Aaron.

"I Have The Body Of A God... Buddha"
Junk Yard Genius is offline  
post #8 of (permalink) Old 12-01-2000, 10:38 PM
**DONOTDELETE**
Guest
 
Posts: n/a
Re: Picture of my bad jeep spark plugs


"The top plug was either Mechanical Damage"
<font color=red> I don't think so? </font color=red>



"You have to remember that the hard parts of that spark plug are probably imbedded in the top of your piston..."
<font color=red> Is this something the head should come off or do you think it could of spit it out the exhaust?</font color=red>


"Go back one or two heat ranges, use premium fuel when towing, and don't lug the engine when it knocks."

<font color=red>I will not run a engine where it will ping or knock-BUT-This damage had to happen somehow.From here on out I will run the premium fuel when pulling or trails. Thinking about this I probbly lug this engine worst on trails because of the 3.31 gears. Just thinking the first time this engine started acting up was after my son and I did some trails. I blamed the bbd carter carb. Then did a rebuild of the carb. Then started fighting flooding when I would shut the engine off . drop the float but then would run out of gas on the harder pulls. So there we go with more lean running. Put a fuel pressure regulator on the jeep and cured the flooding but probbly made the lean thing worst. when I got done with the TR upgrade I found that I had to raise the fuel pressure more.It smoothed the engine so i could feel it was lean . I have read that one cannot hear all the detonation. That it is happening before you can even hear it?</font color=red>


"If you use one of those little coins to gap your plugs by prying down on the center electrode, you stand a 50/50 chance of ruining the spark plug before it's even installed.
NEVER PRY ON THE CENTER ELECTRODE FOR ANY REASON!!
Get a pair of needle nose pliers and grab the ground electrode, and bend it away from the center electrode....
What you have is what is left after you crack the porcelain.
That is also what is left after one is detonated to death, so I can't be sure."

<font color=red>I will take your advice to heart. Yes I use a coin thing but. I did not gap the plugs that are in the engine. The jeep came with them. They have about 25000 mi on them.</font color=red>



"The ignition is updated to the '90's, so maybe you should use a plug with the same heat range of say, an '92 or '93 or so Ford truck, and see if that helps...
SAME HEAT RANGE, NOT THE SAME PLUGS...
Plug reach should be considered here, and I just haven't done any research on the differences in plug reach or threading, or the taper or gasket method of sealing."

<font color=red> I will check into this.</font color=red>


"Believe this or not, a vacuum gauge will tell you if a plug (or plug wire or cap and rotor problem) is doing something stupid...."

<font color=red> Love vacuum gauges Have run one in our 86 Ford van from when it was new. Great to see if one is lugging the engine when hiting a head wind or towing. 192,000 mi. engine,trans,rear, never been touched. Other than timing chain,fuel pressure reg.,alt.,seals in the rear.</font color=red>


"Did any more of the plugs show signs of taking a beating or over heating?
Are you keeping a CLOSE check on the new plugs?"

<font color=red> I will be keep an eye on them. Have not had time to really drive the Jeep . Just around town. Only 300 people in this town so don't even get the engine warmed up good.</font color=red>




"This is one of those problems where there are usually several contributing factors that manifest into one large problem.
Don't kick yourself over this one. It's usually unforeseeable, and it's very fixable."

<font color=red> I think you hit the nail on the head here. Detonation and lean fuel I think had a hand in this?</font color=red>


If you still have problems, e-mail me, and we will go over the finer points of how to track this down.... [email protected]

<font color=red> Thank you T.R.. The information you have posted here and other post are priceless. The best praise I can give you is I'm going to e-mail this to my Dad .He is 75 and cannot work much on engines any more but loves any good information he can get like this. With moveing the oldest boy from school helping Mom and Dad ,Dad,s lite heart attack, Wife's cancer scare, abused grand kids ,under staffed at work. I fear the jeep has taken a back seat when it should of been looked at. Got a few days off so been hitting it in the drive way 20 deg with a wind and snow blowing right up one's butt. takes the fun right out of it. This is really a good engine don't use no oil and I try to take care oof it . So I do feel bad and will try to fix the probblems.</font color=red>









Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Off-Road Forums & Discussion Groups forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome