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Scott99Cobra
07-07-2004, 10:12 PM
Just wondering what plugs to get. I have a '99 Cobra with 16K miles. It idles rough sometimes, so I thought maybe it is the plugs. Are the Iridium plugs woth the extra $'s or should I just stick with the stock plugs. I have no mods - unless you consider a drop-in K&N a mod. Also, how much anti-seize should I use? What about a torque wrench? Any help would be appreciated! As you can tell, I am not real mechanically inclined.

tcrews
07-07-2004, 11:02 PM
Just wondering what plugs to get. I have a '99 Cobra with 16K miles. It idles rough sometimes, so I thought maybe it is the plugs. Are the Iridium plugs woth the extra $'s or should I just stick with the stock plugs. I have no mods - unless you consider a drop-in K&N a mod. Also, how much anti-seize should I use? What about a torque wrench? Any help would be appreciated! As you can tell, I am not real mechanically inclined.

Get some Autolite 764 copper plugs and gap them at .054, cheap and a very nice plug (about $1.00 each). Iridium plugs are a complete and total waste of money...period. I don't think plugs are causing your rough idle though....when did it start (andy changes right before the rough idle, etc..)?

Dirty MAF, dirty IAC, vacuum leak can all cause a rough idle. Unless your plugs are really fouled they probably aren't the cause.

Scott99Cobra
07-08-2004, 08:16 AM
Get some Autolite 764 copper plugs and gap them at .054, cheap and a very nice plug (about $1.00 each). Iridium plugs are a complete and total waste of money...period. I don't think plugs are causing your rough idle though....when did it start (andy changes right before the rough idle, etc..)?

Dirty MAF, dirty IAC, vacuum leak can all cause a rough idle. Unless your plugs are really fouled they probably aren't the cause.

The only thing I have done is a drop in K&N and a PRO 5.0. I do get a hissing sound at around 2K that I have not been able to track down. It may be a vacuum leak like you mentioned. I have checked all the hoses but have not found anything loose. Any thoughts?

01BlueCOBRA
07-22-2004, 01:26 AM
AutoLite double Plat. good plugs also gapd at .054 =]

tcrews
07-22-2004, 07:56 AM
AutoLite double Plat. good plugs also gapd at .054 =]

no no no no....stay away from platinum plugs :) Platinum plugs do not conduct as well as copper plugs. Car manufacturers use them because they last longer (100,000 mile change) vs. a copper plug (50,000 mile change).
Autolite 764 (copper) plugs gapped at .054 are your best choice. Inexpensive, readily available and an excellent performer.

ausie
07-23-2004, 07:25 AM
My cobra is an 01, similar to the 99. I have had too many issues with plugs to mention (due to carbon build up and pinging). As a last resort, I switched to Denso Irridiums (they cost more than you would want to pay for plugs). What caught my eye was an article in Muscle Mustangs & Fast Fords as well as the written requirements for the use of Kene Bell superchargers.

The issues I had were that normal plugs would get fouled up within 500 to 1000 miles. I had Ford check out my motor to see what they could do for it, their reply was it is not covered under warrenty (3yr 36k miles, car had 6k miles on it at that time). So I was left on my own to discover the problem.

It turns out that the EGR valve was at fault. After replacing it at 20k miles I have not had any problems with pinging or noticed carbon build up on the plugs. At that point, I changed to the copper autolights, they worked fine unless you punched it then it would ping a little and it seemed a bit on the sluggish side. I decided to put the old desno's back in which had 10k miles on them. I could notice a difference immmediately. I did not buy them as a performance issue thinking I would get more gain, since I do not have forced induction there is no benefit, however, the car does not suffer from loss of power due to pinging when using other plugs.

The Denso Irridum plugs cost more per plug than a full set of the autolights, but I am pleased with them and find it hard to go back to using other plugs. At first, I think my car was running on the lean side. Since I have been able to clean out most of the carbon deposits (water injection cleaning, lots of TB cleaner, and replacing some parts that were covered under warrenty that ford did not want to bother with, and along with installing a free flowing cat back) the carbon has not returned. I have yet to re-try the autolights which only had 100 miles on them since the cat back, I just found the denso to work better (just my opinion).

It is best that you get what you think works best for your car. The autolite plugs are a good plug for the money. Irridium plugs may not perform as you expect them to.

A rough idle indicated you may have oil deposits on the MAF since the lower amount of air is passing through the intake, if there are oil deposits from the filter on the element, it may idle rough, Try using electrical parts cleaner on the MAF element (with engine off!) That could make a huge difference. I used to suffer that problem, until I went back to a paper filter. Even the AMSOIL dual stage filter seems to hinder performance a bit (causes the idle to stick around 3000RPM occasionally). I can agree that the K&N flows more air, but it also flows more dust and dirt too which tends to gunk up all the intake parts.

Maybe my car is an odd ball, but I find that if performs better with stock parts on the intake side of things. Oh well, so much for that.

Scott99Cobra
07-23-2004, 10:21 AM
Thanks for all the replies. I have not done anything yet with the plugs, but I may take a look at the MAF. Sorry I have to ask this, but exactly where are the wires that I should clean with the electrical cleaner? Can you use a fuel injector or carb cleaner instead?

ausie
07-24-2004, 10:05 AM
Yet another long post, :D hope this helps those in need, or if anything inspire others to disagree, perhaps I will learn something new;

The easiest way to clean the MAF is to remove it from the air channel. First you will need a security torx bit (it looks like star bit with a hole in the middle, I am not sure what the size is, I just bought the small kit that had various sizes). The MAF is held in place by two screws. Just remove them and carefully pull up on the MAF. The part to clean is on the under side of the sensor (you will see two tiney filiments on two separate ceramic cores.

Those are the wires that need to be cleaned. It is best to use electrical parts cleaner (you can get that in a small can at the auto shop where you get the torx bits). If you ust TB or fuel injector cleaner it will leave an oil base on the part which is not what you want. You can use isopropal alcohol and a Q-tip, but sometimes cotton from the Q-tip will come off too. It is best not to touch the wires, so electrical parts cleaner is the better solution.

How it works: The wires in the sensor get hot during operation to the point of glowing like a light bulb. The air flow passing over the wires changes the resistance of the wire and the current flow through the wire. This change in current and resistance is monitored by a current sens resistance which is fed back to the computer.

It is best to clean the sensor with chemicals that do not deposit lubricants on the part which may hinder the the operation of the sensor. I also found that the electrical parts cleaner works great on spark plugs too. As well as the IAC valve solenoid shaft.

Most TB and fuel injector cleaners should only be used as they are intended since they will remove the varnish on the wires of solenoids and electical motor windings since that is thier intended purpose.

If you found that your car accelerates like a slug and is not quite the same as it used to be, cleaning the MAF can make a world of difference. It is a good thing to make cleaning the MAF, as well as cleaning the intake plenum, throttle plate, etc as a routine maintanance task which can be done prior to changing the oil if you do that on a regualr basis. I usually go beyond what is necessary and probably over kill, but so far the motor has not detonated since I have included several things in my maintance schedule. In actuallity, it does not add more time since I can do the cleaning part during warm up of the motor prior to oil changing.

Scott99Cobra
07-24-2004, 05:02 PM
I pulled one of the plugs out today and it was a AWSF32E. From other threads I have read the right plug should be a AWSF32C?

ausie
07-25-2004, 12:53 PM
I tried to look up numbers, and could not find anything. If you have the 4.6L you should be using resistor type plugs since the coil is directly mounted on the plug. I have often found that Ford did not always use the same plug during assembly and that there are alternates used (depending on model, year and date of manufacture). In most cases, the amount of threads on the shank of the plug may be different. (either the threads go half way up or all the way up). Both will fit, but the fully threaded shank will allow for chamfer cut on the plug to seat with the heads. When changing your plugs for the first time, always bring an old one with you since there are probably different style threads and seats used on plugs having the same basic part number. The difference may be the region of manufacture of the motor such as Romeo Michigan or Windsor Canada. Ford uses the same plug for most of the motors produced which are not application specific. You could always go to a local parts shop and compare the part numbers in a cross-reference book. Perhaps the other part number is what you should have. I have looked at two different autolite plugs that I have used in my 01 cobra, they were very much the same however, on had a full threaded shank and the other was a half threaded shank. Both worked fine.

ausie
07-25-2004, 01:54 PM
oh yeah, you should use anti-sieze on the plugs since you are installing steel threaded part into an aluminum bore. Always install the plug by hand until it seats then use a torque wrench to tighten it into place (this will avoid cross-threading). Also in some cases you will need an extension with a spark plug socket mounted on it - not an extension with a separate socket as with the case with the SVT since the plug is dead center of the cylinder and has very deep ports, if the socket slips off the extension, it will be very difficult to remove. This may be different with the GT or the V6 motors so that may not be necessary to have a fused extension socket.

I have used the metallic anit-sieze compound and you do not need very much. It is best to use a small amount and spread it around the threads with a paper towel. Avoid getting any on the tip of the plug since this compound will conduct. This stuff stains too, if you get it on your hands it will remain there for a long time and is difficult to clean off the skin.

:zz: One last point, the use of platinum plugs does not mean they will last 100k miles. Ford recommends replacement at 40k miles. I usually pull one or two plugs at every oil change to inspect for any abnormal deposits. Usually every 10k miles I pull all the plugs for inspection. Check the gap, and or clean the electrode with an old tooth brush and electrical parts cleaner.

As far as the metals used, it does not matter if it is copper or platinum plating on the electrode. Sure copper conducts current better than platinum, but at the applied voltage in excess of 20KV it matters not what the material is made of. Copper is better used with speaker wires or low current applications where it is superior to most metals except silver. At high voltages and high currents where arching across a gap is desired, the harder the material used the longer it will hold up from the heat generated in the spark. Most likely the conductor used in copper plugs is a nickel copper alloy.

:drool: All that should matter is cost of the plug and how long it will last. It will not matter if it is platinum plated, copper, irridium, or steel, the intensity of the spark is a relationship of the gap, the wider the gap the higher the voltage has to be to cross the gap. The only thing that matters is how well the metal holds up to the plasma flow in the arch, some metals will melt or burn off and others will suffer intermetallic deposits that will hinder current flow which is related to electron movement and metal migration that occurs within the conductor itself.

:doh2: sorry for getting boring. Most motors will work fine with the run of the mill standard plug. Some may work better than others in the long run. The only time you need to use a different plug is when you have forced induction or power adders such as superchargers, turbos and or nitrous, and of course the choice of fuel used such as nitro methane or mentanol alcohol.

Scott99Cobra
07-26-2004, 09:02 AM
Thanks, ausie. I pulled one of the plugs this weekend and it looked fine. With only 16K I didn't really expect it to look too bad. I didn't get much more done than that - other than giving her the weekly bath/detail.

ausie
08-01-2004, 02:07 PM
Yesterday I decided to perform a complete intake cleaning since it started pinging slightly when using the AC. Also I wanted to check the plugs since I re-gapped the denso irridiums to factory spec (0.052" instead of the 0.045" which worked perfectly). When I gapped them the plugs appeared normal. After 1000 miles later and since I was tearing down the complete intake, fuel injectors, etc. why not pull the plugs too. Why take out the fuel injectors? That gives you a direct shot to the valves (almost) for TB cleaner not to mention an opportunity to clean the injectors. I was reading about the IMRC's on the older Cobra's in which I do not think the 01's have them, but if I do a little TB would clean things up a bit. I also noticed that the plugs did not look normal (flat rust colored with some metalization on the insulators, not good). Out with the denso's and in with the autolights (I decided to give them another try, and besides that I had them sitting around with only 200 miles on them.) Sooner or later I will have to re-flash the processor with a better fuel curve. The factory program runs on the lean side. Just one step closer to running like new. I would go back to the Motorcraft plug but nobody seems to cary them except the Ford dealer and I do not want to pay that kind of money which would be close to the cost of the denso irridiums.

Scott99Cobra
08-01-2004, 06:11 PM
That stinks. So, do you think your best performance was with the stock plugs and none of the others you have tried? Or, is it more that the stock plugs seem to hold up better than the others? There seems to be a lot of interest in the Brisk plugs right now. However, at about $90 per set you would like to hear some dyno stories as to how they performed.

ausie
08-03-2004, 06:53 AM
To be honest, I had the best performance with the denso plugs with the gap set to 0.045". The rusty color is probably due to fuel additives. It only pings when power shifting with the AC on which is not that noticable. I do notice a difference with the other plugs (slightly sluggish) when compared to the Denso's. It is also probably due to the temperature and humidity too. Since I experienced severe carbon build up in the past to the point you could see it caked on top of the pistons when looking into the sparkplug hole with a flashlight. Over a long duration of using Mobil gasoline 93 octane caused the build up. I can only use BP or Hess gas since all other fuels detonate. One thing is for certain, the carbon problems have been reduced ever since I installed a less resitrictive cat back exhaust. I can only guess how clogged up my cats are. One probable cause for carbon build up would be oil consumption in the combustion chamber either caused by piston slap or transfer of oil throught the PCV or breather hose. I suspect most of the oil consumed is from the PCV line since there is noticable oil in the line. I could probably cure that with a PCV catch can (which will be my next mod).
Unfortunately, it still pings with the new plugs. I will eventually clean up the denso's and put them back in since they are still in good condition. The metallics on the insulator are probably a result of over-gapping them. Time to clean them up and put them back in.

I will have to check out the Brisk plug design to see if they are useable. Considering the other plugs, they basically last 3000 miles at most before needing replacement since they would start to misfire due to carbon deposits. If they were wet or if the gap was contaminated then I would suspect something else. Even ford was baffled why plugs only last so long. Their suggestion was that I baby the car too much. Total BS! The way I drive it, I am lucky so far not to get a ticket. Then again, black cars seem to go unnoticed. Besides that, I know where the sit so I usually do the speed limit in those areas. :D .

Only one thing, since I have been off topic, a good cat back increases fuel buring efficiency to some extent, having long tube headers and either better cats or no cats would help too. Forced induction will also help a little (I think).

Scott99Cobra
08-16-2004, 10:21 AM
This weekend I cleaned the throttle body and went ahead and sprung for the NGK irridiums($6 ea. at O'Reilleys). I haven't driven it a whole lot since, but the idle is smoother and it seems to rev a little easier/smoother. I also used to have a slight "dead" spot just off idle that was noticable between shifts that has gone away - for now anyway. I also put in a bottle of Chevron Techron last week and that seemed to help the dead spot also. So, not any big improvements, but enough to make it worth it for me.