Tacoma spark plugs

[Shinneryfarmer]

Thing is about plug gaps is try and see what works best for you.
Its free to do so.
I like trying free things.

Agree 100%, work on natural gas industrial engines that run 2100 hrs before a service is required. Had issues with sparkplugs misfiring and being replaced before specified service intervals. By tightening the gap to .011 misfires became nonexistent and plugs would exceed service intervals and by cleaning and regaping to .011 would run another service ($150 per plug x 16). Even on my personal vehicles if I see signs of misfires I tighten the gap to alleviate the issue and usually reap other benefits, mpg or performance.

 

[montesa]

Agree 100%, work on natural gas industrial engines that run 2100 hrs before a service is required. Had issues with sparkplugs misfiring and being replaced before specified service intervals. By tightening the gap to .011 misfires became nonexistent and plugs would exceed service intervals and by cleaning and regaping to .011 would run another service ($150 per plug x 16). Even on my personal vehicles if I see signs of misfires I tighten the gap to alleviate the issue and usually reap other benefits, mpg or performance.

I wish I would have tightened them now! I didn’t read anything on this on the Toyota forums. I do think I remember now that when I changed them years ago, I had the same question and left them the way they came and they lasted a long time. The engine I have is very low performance and that probably has something to do with it.

 

[montesa]

Now I’m thinking I’ll redo the job, tighten the gap and put in all new coil packs at once. It’s not a big job by any means and it’ll be worth it to have it set for another 100k no with no problems.

 

[Shinneryfarmer]

I wish I would have tightened them now! I didn’t read anything on this on the Toyota forums. I do think I remember now that when I changed them years ago, I had the same question and left them the way they came and they lasted a long time. The engine I have is very low performance and that probably has something to do with it.

Just look at it this way the gap as it gets wider requires more voltage to produce same spark. But at a point your limited on voltage to override this gap thus creating a weaker spark. Thereby producing incomplete combustion which uses more fuel to generate required horsepower. Now tighten that gap and you have a hotter spark completely burning all the fuel in the cylinder each cycle making 100%(or as close to it as you can get) available horsepower thus using less fuel. This also reduces stress on coils to produce the voltage to jump that gap.

 

[swampratt]

Hold on.
If your vehicle does not misfire with the current coil packs then keep them.
You know aftermarket coil packs may not be nearly as good as what you have now.
Cosmetic damage is not a reason to replace them.
Pop the hood at night in the dark with engine running.
Do you see any sparks coming out of the coil packs?

If no then run them.
I can easily fill a 55 gallon barrel with all the failed New parts I have bought for my personal vehicles.
Not counting other peoples vehicles.

Run a tank or 2 of fuel with the gap as is and then tighten it and see if you get any difference in MPG.

You may not.
But tighter and you will know it is easier on the coils.

 

[montesa]

Just look at it this way the gap as it gets wider requires more voltage to produce same spark. But at a point your limited on voltage to override this gap thus creating a weaker spark. Thereby producing incomplete combustion which uses more fuel to generate required horsepower. Now tighten that gap and you have a hotter spark completely burning all the fuel in the cylinder each cycle making 100%(or as close to it as you can get) available horsepower thus using less fuel. This also reduces stress on coils to produce the voltage to jump that gap.

I understand the concept. However, I wonder why the factory specs a larger gap. Also these are iridium plugs and they are supposed to wear much more slowly.

Wouldn’t a larger gap provide more complete combustion assuming the coil has enough power for the compression range and the spark plug designed for the engine?

 

[montesa]

Hold on.
If your vehicle does not misfire with the current coil packs then keep them.
You know aftermarket coil packs may not be nearly as good as what you have now.
Cosmetic damage is not a reason to replace them.
Pop the hood at night in the dark with engine running.
Do you see any sparks coming out of the coil packs?

If no then run them.
I can easily fill a 55 gallon barrel with all the failed New parts I have bought for my personal vehicles.
Not counting other peoples vehicles.

Run a tank or 2 of fuel with the gap as is and then tighten it and see if you get any difference in MPG.

You may not.
But tighter and you will know it is easier on the coils.

Well, I just ordered four new coil packs. I know you’re right but I’ll save the non cracked ones as spares.

I only buy Toyota Factory parts or the OE manufacturer. Bought denso brand which is who makes the OE. 50 bucks each!

 

[Shinneryfarmer]

I understand the concept. However, I wonder why the factory specs a larger gap. Also these are iridium plugs and they are supposed to wear much more slowly.

Wouldn’t a larger gap provide more complete combustion assuming the coil has enough power for the compression range and the spark plug designed for the engine?

A larger gap will provide more efficient combustion provided all is perfect. Not to be misunderstood I stated as that as gap increases the coil may not have sufficient voltage to maintain a hot spark thus reducing efficient combustion. At some point the gap becomes to wide for the coil to overcome for sufficient spark. I have seen this in as little as .005 when the gap spec is .060 on older engines. Reduce gap to .045 or.050 and issue is resolved. When auto manufacturers set specs for numerous things that is in a new engine under perfect conditions. They do not take into account every aspect of conditions that happen over time. Wear on mechanical parts, weakening of coils and other electrical components. The specs they set on a new engine may not be as efficient on a engine that has 100k on it for these various reasons.

 

[swampratt]

Wouldn’t a larger gap provide more complete combustion assuming the coil has enough power for the compression range and the spark plug designed for the engine

If all the above were able to be obtained then plug gap should not matter as far as more complete combustion.
You will have a lot of turbulence in a combustion chamber way more when boosted.
You can actually do something that is called blow the spark out.
Tighten the gap or switch from a projected tip plug to a non projected tip plug and realize gains.

For the majority slow drivers that never see above 4500rpm larger gap will probably never hurt anything.
Again testing to see what you get is the best way.

If i had pulled that plug of yours from my vehicle and seen the center electrode worn away and rounded off i would look very closely for tiny Easter eggs on the plug.
Basically tiny balls of dull aluminum.

I would also pick a heat range a little cooler as that is too much wear for me.
But i do realize the miles put on that plug also has a lot to do with it.

My cars all crank over 200 PSI and i full throttle them every time I drive them.
Tune is important to me

 

[montesa]

A larger gap will provide more efficient combustion provided all is perfect. Not to be misunderstood I stated as that as gap increases the coil may not have sufficient voltage to maintain a hot spark thus reducing efficient combustion. At some point the gap becomes to wide for the coil to overcome for sufficient spark. I have seen this in as little as .005 when the gap spec is .060 on older engines. Reduce gap to .045 or.050 and issue is resolved. When auto manufacturers set specs for numerous things that is in a new engine under perfect conditions. They do not take into account every aspect of conditions that happen over time. Wear on mechanical parts, weakening of coils and other electrical components. The specs they set on a new engine may not be as efficient on a engine that has 100k on it for these various reasons.

Ok got it thanks. Just wanted to make sure I wasn’t thinking about it in the wrong way.

The larger gap may also be for meeting emission standards and not optimal running.

Swampratt, I checked, didn’t see any aluminum. Would these be from pinging and possible erosion of valves or the head?