Spark plugs, what are they telling me?

[heathhh]

Heres 2 pictures of my spark plugs. Picture one, showing cylinder 1-3 spark plugs, and second picture showing 4-6 spark plugs.
Grumpy and or another could tell me whats goin on inside my engine?

Links
Picture 1- http://i47.tinypic.com/spdxme.jpg
Picture 2- http://i47.tinypic.com/2n6erg2.jpg

Basic info first-
1982 280zx N/A
Has a engine tick, lifters.
poor idle

I have a bad idle issue, and had talked with Grumpy over the phone. I had told him what ive done pertaining the next step towards my fix. He said i could start by registering here and look around and learn all the knowledge that i can. Which i have begun and will continue to do! I have verified compression(good), fuel pressure(good), set the timing (for the most part, i do not know about the advance), i have verified i have a vacuum leak according to the gauge it reads about 12-14. The vacuum increases when the throttle is pressed and then when its depressed the vacuum decreases to about 9-11 maybe lower. It slowly builds back up though struggles.


I was told to get a propane torch and carry out vacuum tests that way as it is more accurate. Well, thats a start for me. Ask me anything to further help me and or you to understand the problem i am encountering and where abouts to go to correct it. Thank you, -Heath.

 

[grumpyvette]

ok, first impression,

if you measure the plug gaps ID bet they measure greater than .045 thousands, ..they appear to be significantly larger and that takes a good deal more voltage to jump.
next,
look at the ground electrode, it appears to have its heat band go back to just short of the curved section indicating a retarding ignition or a overly rich fuel/air ratio
next
look at the insulation porcelain, and center electrodes, again both indicate low heat , usually the result of retarded ignition timing or a rich fuel air mix

reading these links and sub links should help

http://www.4secondsflat.com/Spark_plug_reading.html

viewtopic.php?f=70&t=202

viewtopic.php?f=4&t=1337&p=2921&hilit=+infrared#p2921

viewtopic.php?f=81&t=1189&p=2447#p2447

viewtopic.php?f=55&t=109&p=6685&hilit=+fuel+air+ratio#p6685

viewtopic.php?f=50&t=1853&p=4848&hilit=ratio+meter+fuel%2Fair#p4848

viewtopic.php?f=70&t=1809&p=4671&hilit=+ignition+curve+advance#p4671

 

[heathhh]

I actually have only ran the engine in the garage once since the timing was adjusted. Specs said for the timing to be set at 8 (+- 2) at idle. I adjusted it many times the best i could and it is set at 9.

So previously before that the car was adjusted timing, it was driven and ran in the garage many times. So thats why the spark plugs look like that i would say. I will check the spark plug clearance again. The manual specs i believe were large spaces for the spark plugs i thought as well, but that's what it had said for me to do. I will double check though.

As for the vacuum leak somewhere wouldnt that also make it run lean>

 

[grumpyvette]

if you have a vacuum leak , yes that would tend to make it run leaner, step one is gap the plugs at .045 thousands and try running the car and see if its idles better (which it should)

common but not very accurate

slightly more accurate

http://www.sears.com/shc/s/p_10153_12605_00994133000P

good accuracy at a low price

thread chaser

inspection tool

http://www.verrill.com/moto/sellingguid ... rchart.htm

http://www.4secondsflat.com/plug_chart.html

http://www.harborfreight.com/cpi/ctaf/d ... mber=94367
dirt cheap plug inspection tool

viewtopic.php?f=70&t=202

viewtopic.php?f=50&t=1853&p=4848#p4848

 

[heathhh]

I also read up on the spark plug information on the links you had posted. I can refer to those many a times, and im sure that i will when i take spark plugs out. I understand now what it means for the spark plugs and how they each look. Thanks Paul.

 

[heathhh]

I actually have some feeler gauges and will use those to better see what space i am getting. as well as the gap tool. Should i just go ahead and use the same spark plugs? Or is there a way of cleaning them so that they can operate like newer? I have heard of some using a small flame at the end of the spark plugs to clean them but i myself dont know if thats a good idea.

 

[grumpyvette]

new plugs are best but if the current plugs have less than about 20k miles on them they should be fine



heres some good links on tuning
viewtopic.php?f=50&t=383&p=1637&hilit=infrared+tuning#p1637

viewtopic.php?f=44&t=773&p=1123&hilit=infrared+tuning#p1123

viewtopic.php?f=55&t=264&p=877&hilit=+infrared+tuning#p877

viewtopic.php?f=44&t=579&p=743&hilit=+infrared+tuning#p743

reading material

viewtopic.php?f=70&t=202

viewtopic.php?f=55&t=109

viewtopic.php?f=55&t=211

viewtopic.php?f=36&t=768&p=2762&hilit=+propane#p2762

viewtopic.php?f=70&t=1809

viewtopic.php?f=62&t=882&p=1390&hilit=propane+leaks#p1390

viewtopic.php?f=53&t=2921

viewtopic.php?f=4&t=1337&p=2921&hilit=+infrared#p2921


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Tuning Via EGT vs, Wide Band/ Narrow Band Meters

There seems to be a lot of mystery and misinformation about using exhaust gas temperatures to tune engines. Claims by many EGT gauge manufacturers about it being the best way to tune an engine must be qualified. The BEST way to tune an engine is on an engine dyno- PERIOD. What EGT is good for is a reference for where the engine made maximum torque at wide open throttle. Once removed from the dyno, a similar air/fuel ratio can be established at a later date by dialing in the mixture to achieve the target EGT. It is really the AFR that is important, not the EGT. Most engines will make maximum power at an AFR of between 12.0 and 13.5 to 1 however, the EGT may vary from 1250F to 1800F and is dependent on many factors.

It should be mentioned that the target EGT is valid only on the same engine configuration as was used on the dyno. If you change the ignition timing, cams, pistons, headers etc., the optimum EGT may also change. Raising the compression ratio with no other changes will drop the EGT at the same AFR. Retarding the ignition timing will generally raise the EGT at the same AFR. One engine might make best power at 1350 degrees while a very similar engine might be happier at 1500. You can't guess at this or you are simply wasting your money on the instrumentation. Wankel engines have higher EGTs than comparable piston engines due to their lower thermal efficiencies. 1800F is not uncommon here.

Some gauge manufacturers say you should tune to achieve maximum or peak EGT for maximum performance. This is incorrect. Peak EGT generally occurs at an AFR of around 14.7- 15.0 to 1 on gasoline. This is far too lean for maximum power and is dangerous under continuous WOT conditions. Many people think that the leaner you go, the higher the EGT gets. This is also incorrect. Peak EGT occurs at stoichiometry- about 15 to 1 for our purposes. If you go richer than 15 to 1, EGT will drop and if you go leaner than 15 to 1 EGT will ALSO drop. It is VERY important to know which side of peak EGT you are on before making adjustments. It is safe to say that peak power will occur at an EGT somewhat colder than peak EGT.

You can sometimes feel a lean of peak condition as the mixture is hard to ignite and power will be down a bit as well. Once the AFR gets close to 17 to 1 at WOT, generally the engine will start to lean misfire. Most tuners always recommend to begin jetting or programming from a known very rich initial setting and carefully leaning until torque falls off slightly, then going back richer to the point of max torque. Note the EGT at this setting. Be aware that altitude, barometric pressure and ambient air temperature may affect this optimal temperature to some degree.

Are EGT gauges better than AFR meters? Conventional narrow band oxygen sensors and digital LED meters are not the best devices to measure AFR in the richer ranges but they certainly warn of a too lean condition immediately and obviously, without translation by the driver and they are affordable. Meters combined with wide band sensors are supposed to be highly accurate and everyone has jumped on the bandwagon with these lately. Unfortunately the naive and impressionable often don't question the accuracy of these devices. We have seen some dyno plots indicating best power was achieved at AFRs of 9.7 to 1 on gasoline. This is PHYSICALLY AND CHEMICALLY IMPOSSIBLE and shows that either the sensor was bad (leaded fuel used possibly) or the meter was not calibrated properly. Again, the wide band sensors have the same limitations as the narrow band- leaded race gas quickly fouls them. We have heard and read many stories now indicating that certain brands of wideband meters differ as much as 2 points AFR in readings between each other. In other words, the accuracy of some of these devices is highly questionable. Extensive testing with laboratory quality instrumentation on aircraft engines universally indicates that best power is NEVER made at AFRs richer than 12 to 1. Airflow and fuel flow rates are independently measured and each cylinder is instrumented with EGT probes.

We recently dynoed a shop road racing Celica on a DynoJet equipped with a wide band meter. The meter was saying that the engine was going super lean (17 to 1) at high rpm so we kept upping the fuel there. The engine lost more and more power as we added fuel. The dyno operator was convinced that the meter was right but logic told us with no serious dip in power on the curve and the fact that the engine was still alive that the meter was not correct. We started leaning the engine down more and the engine started gaining power. Finally, when confronted with this information, the operator checked the water trap for the wide band sensor. Once this was emptied, the AFRs looked reasonable again. We didn't need the wide band to tell us this, only the torque curve from the dyno.

We have heard of several other instances with people using wide bands getting erroneous readings and tuning their SDS based on these readings. Then they phone us saying that the system is crap. Look at the dyno curve, when the engine makes its best power at a given rpm, that's where it likes the AFR irregardless of what other instrumentation is telling you. Remember, a bad sensor whether O2 or EGT equals bad information. When the engine sounds crisp and makes great power, you're there.

I would suggest that mixture meters and EGT gauges are complimentary. EGT gauges have the advantage of working long term with leaded fuel which will clog oxygen sensors. EGT gauges are widely used to set mixture on engines used for steady state high power applications where operation has been carefully documented such as in aircraft. The choice would depend on the application. Both are better if you can afford them.

 

[grumpyvette]

it certainly won,t hurt to have access to a fuel/air gauge

Edelbrock 6593 Air/Fuel Ratio Gauge

http://www.summitracing.com/parts/EDL-6593/


fast air fuel gauge

http://www.summitracing.com/parts/FST-170402/?rtype=10

rsr air fuel gauge

http://www.rbracing-rsr.com/rsrgauge.htm


innovative

http://www.innovatemotorsports.com/products/MTXL.php


http://www.competitiondata.com/air_fuel ... _vs_nb.htm
viewtopic.php?f=55&t=6765&p=25598#p25598

If you do a little research you will find lots of “Air/Fuel Meters” on the market priced in the $100 to $ 400 range. These are “narrow band” products based on production car Oxygen or Lambda sensors. You will also find products priced at $ 1000 to $ 4000 per channel and even higher. These are wide band products.

What’s the Difference?

Wide Band

* Shows Actual Air/Fuel ratio.
* Precise display of ratio on the rich side of “stoichiometric”, which is where all performance engines run. Usually displays Air /Fuel ratio to the second decimal place.
* Useful for maximizing power from race and other performance engines.
* Fully temperature compensated.
* Higher cost.




Narrow Band

* Shows indication of rich vs lean.
* Usually has very “coarse” display of ratio on the rich side of “stoichiometric. Some units only have 2 LEDs for the entire rich range!
* Really only useful for making sure your engine is not running on the lean side.
* Usually not temperature compensated, so the same air/fuel condition in the motor will result in an indication on the meter that will vary depending on sensor temperature.
* Low cost.



Bottom Line:

If you are a builder or tuner of performance engines who needs to maximize performance of the engines you work with, then you need to be measuring Air/Fuel ratio with a wide band meter.

If you simply want an indication that you are rich or lean to make sure you are not going to burn the motor up, you can get by with a narrow band meter



Narrow Band vs. Wide Band Air Fuel Ratio Meter

An air fuel ratio meter is a type of gauge that is used in cars, boats or any vehicle that has an internal combustion engine. Its job is to detect how much voltage is emitted by the engine’s oxygen sensor, and in so doing, it can gauge the engine’s air-fuel ratio. Air fuel ratio meters are important because they help to ensure that your vehicle is using fuel efficiently, helps your catalytic converter to work optimally and thus cuts down on toxic emissions, and maximizes the engine’s performance in general. Nowadays, there are 2 types of air fuel ratio meters on the market: narrow-band readers, and wide-band readers. Keep reading to find out how the two are different, and their pros and cons.
Narrow Band vs. Wide Band Air Fuel Ratio Meter: Physical Qualities

The narrow band meter has long been the standard in cars, although now it’s becoming a bit antiquated. They are present in your car in a round-shaped housing. Like the other gauges in your car, the mounting usually measures in either 2 1/16 inch diameter or 2 5/8 inch diameter, with 10 to 20 LEDs. Some are available with a needle-style gauge interface. The reliability of the narrow band meter can be negatively affected by increasing gas temperatures, so they have to be used with care.

www. Siemens. com/ Air_Flowmeters


Wide band meters are newer and more accurate. They can either stand alone or be mounted in round housings also. Unlike the narrow band meters, these have a numeric display, and can display much more sensitive and accurate information. They have a linear output of 0 to 5 V and can function no matter what the temperature of your car’s engine.
Narrow Band vs. Wide Band Air Fuel Ratio Meters: Which One Should I Use?

If you have an older car that you just need to check on from time to time, especially if you suspect that something might be wrong with the oxygen sensor, then a plain old narrow band reader will probably do just fine. These models are cheaper, and as long as you’re not worried about getting a very sensitive reading, then the narrow band should do just fine.

On the other hand, if it’s your treasured sports car that we’re talking about, or if you need to perform some really sensitive, highly refined maintenance, then you should really spring for the wide band meter. The wide band meter gives you more accurate information, gives you more precise numbers, is reliable no matter the temperature and is easier to read. If you feel that there’s a lot at stake for the health of your car, then, it’s worth the extra investment in a wide band air fuel ratio meter.


Read more: http://www.doityourself.com/stry/narrow ... z104zOE8IJ


Read more: http://www.doityourself.com/stry/narrow ... z104z4RvcZ

read these links below

http://autospeed.com/cms/title_InCar-Ai ... ticle.html


Here's some good reads for tuning carbs with an A/F logger:
http://www.innovatemotorsports.com/reso ... ileage.php
http://www.innovatemotorsports.com/reso ... g-hero.php
http://www.innovatemotorsports.com/resources/Stan1.php

Here's a quote at the Innovate Motorsports website that inspired me:
"A carbureted engine can produce just as much horsepower as a fuel-injected engine. The trick is tuning. Probably the main advantage of fuel injection is its "tune-ability." With an LM-1 air/fuel ratio meter, and a little knowledge, any carburetor is tuneable."

Other links are here at the Innovate site:
http://www.innovatemotorsports.com/reso ... entral.php
http://autospeed.com.au/cms/article.html?&A=2191