Topic: How much gap should my Spark Plugs have?

[jfrabat]

Hey, guys, I know this has been answered somewhere, but I just cant seem to find it.  I want to know how much gap I should have on my spark plugs given the fact that I have a 42,000V Accel Coil and high performance sparkplug wires. 

The sparkplugs that are currently in the Jeep were installed by someone else, so I dont know what gap they currently have or if they were gapped at all or not, but if I am going to pull them out, I want to know what gap I sould have to adjust them while I am at it.

By the way, what is the correct procedure to gap the spark plugs?  I am learning as I go, and gapping spark plugs is new to me, so the more detailed the explanation, the better!

Felipe

[blacknblue]

Stock gap on a 2.5 is 0.033-0.038in generally speaking 0.035.  This can vary depending on what plugs you have and not all plugs can be gapped.  The best way is to use a wire gauge instead of a feeler gauge because you can use the tool that is built into most wire gauges to adjust the gap by bending the side electrode until the wire can pass thru with a slight drag.  You should check out http://www.centuryperformance.com/spark.asp to learn more.  Some coils like the one I have from performance distributors allow you to gap up to 0.065.  Bigger gap = Bigger spark.   
Look into what Accel recomends.  It's not all that expensive to just replace all 4 plugs and most should be gapped correctly from the manufacture.  You should replace the spark plugs every 30,000 miles or 24 months which ever comes first.  I'd also look into getting a Haynes repair manual for Jeep Wrangler available most every were...it has helped me tremendously with every vehicle I have owned.

[blacknblue]

One more thing to remember is to carefully thread them in slowly as to not cross thread em and use a torque wrench,  adjust it to 25ft. lbs. 

[GreenBayjeeper]

One more thing to remember is to carefully thread them in slowly as to not cross thread em and use a torque wrench,  adjust it to 25ft. lbs. 

+1 on the torque wrench advise.  Seems obvious, but over or under tightening both cause problems.

A trick that I learned many years ago (most of us probably did too...) is to take an old spark plug wire, cut the boot off, and use it to start the threads on the back 2 cylinders.  They're buried pretty good, and those of us with big hands (or in my case clumsy hands) can use the extra reach.

[lanulos89]

it says it under the hood

[neale_rs]

Clean around the plugs before taking them out so you don't get crud in the engine when taking them out or putting them back in.  You can use a short length of fuel hose to start them in the threads and a torque wrench is a must, you don't want to mess up these threads!  I'm sure you can go with a larger than stock gap with your coil but you may need to experiment to find out what works best for you.

[jfrabat]

Thanks, guys!  I do have the torque wrench and the Chiltons (that states only the stock gap, but I wanted to know what the gap should be given my aftermarket coil).  I will get a wire gauge to measure.  By the way, which spark plugs do you recommend?

Felipe

[GreenBayjeeper]

I don't know that I "recomend" any, but I run regular ole Champion plugs.  I have the DUI Livewires, with their Screamin' Demon coil and cap/rotor.  With that, I gapped my Champions out to .065

For what its worth, I don't think any gimick plugs are worth it in our motor.

[Jeffy]

PD sent my Autolite Platinums so I have no complaints.

[jfrabat]

Can I just gap the ones I currently have in the Jeep?  I changed them only about 7,000 miles ago...  Or is it recommended to gap them while they are new only?

[Jeffy]

Can I just gap the ones I currently have in the Jeep?  I changed them only about 7,000 miles ago...  Or is it recommended to gap them while they are new only?

You will want to clean them up with a wire brush then regap them.  Also take note of the color of the tips.  That will tell you how your engine is running.

[jfrabat]

You will want to clean them up with a wire brush then regap them.  Also take note of the color of the tips.  That will tell you how your engine is running.

Then I'll go in this direction...  Free is a very welcome term for my Jeep budget!  LOL!