Spark Plug Gap

[Defiant]

ive never gapped a spark plug before.... how and what tools do i need.. or does anyone have a site that could help me out???

Ah, the always-forgotten Technical Articles:
http://www.dsmtuners.com/forums/showthread.php?t=174130
Note the admonition to use a wire gauge instead of other types. Or, invest in a pair of gapping pliers.

 

[JayRolla]

I just put on some msd wires and ngk plugs gapped at .28. Now I get a miss fire at about 6k rpm everytime. Do you think that the gap could be the problem? Should I raise it to about .30 to see if that helps. I rechecked the gap and they are correct at .28.

 

[diablos991]

Give that a try.
Also, check to make sure that your wires are making a nice solid connection.

 

[JayRolla]

Yea Ive done that, im hope its not my new msd wires. Those things are expensive as hell. If the plugs dont fix it im going to swap my old wires on.

 

[CanadianTSi]

Opening the Gap will probably just make it worse...

 

[MyBeatGSX]

I had to gap mine down to .025 to keep it from misfiring. But I'm also running the garbage COP. And yea, opening the gap is most likely going to make it worse.

 

[JayRolla]

Thats what I was thinking, that it may make it worse. Im running real low boost also. Should I try to lower the gap a bit.

 

[No_Skillz]

0.028, right?
...^

 

[fourreGsixty3]

I would try a .026 gap. If it doesn't work then swap the old wires back on to make sure its not the MSD wires.

Dustin

 

[MyBeatGSX]

0.028, right?
...^

Didn't even catch that.

That would explain everything.

 

[nightspeed87]

my ngks are gapped to 0.32 or something like that because thats what the ngk thing recommened to gap at. There in a motor im currently dropping in so I havent driven with them yet. Do you think I should lower the gap also if the are a problem when gapped wider?

 

[fourreGsixty3]

That would be one helluva gap RJ I think you mean.032 gap. yes there can be problems when gapping them too wide...Im going to try and find the thread. Something to do with if its too far apart its too hard for the spark to make the jump. to add a little more, if the stock ingnition is upgraded, and you are running high boost, and n2o a wider gap is good, I would gap stock anywhere from .026-.030, I wouldn't go past .030 on stock ignition set-up.

Dustin

 

[nightspeed87]

ok So how do I take the gap down, like just crush it down a little then use the little gap tool and see where its at?
And what gap do you recommend, I have 8:5.1 compression, hybrid 1g/2g timing maps ( more similar to 2g maps. ) a stock ignition but bigger plug wires, full exhaust, a little over stock boost, stock smic, hardpipes, ported 14b, and a 11.1 air fuel ratio.

What gap does it sound like I need?

 

[fourreGsixty3]

Honestly, Im not sure how you would make the gap smaller, I guess you could do what you mentioned, or wait to see what someone else says. As far as gap, I would say the concensious is the .028 is the happy medium, so I would go with that, thats what I went with on my NGK BPR6es', and I had no problems.

Dustin

 

[nightspeed87]

Honestly, Im not sure how you would make the gap smaller, I guess you could do what you mentioned, or wait to see what someone else says. As far as gap, I would say the concensious is the .028 is the happy medium, so I would go with that, thats what I went with on my NGK BPR6es', and I had no problems.

Dustin

Yea thats what I have

NGK BPR6es',

{jayrolla}

The guy who started this thread is using 2g pistons... ( I am also )
I am wondering is the higher compression contributing to his misfire
according to his gap set? Would higher comp require a lower gap, or higher?
Any knowledgeable ppl with some wisedom on this?

 

[JayRolla]

The weather got real cold the day I swapped the wires and plugs. I used to get a miss fire last year sometimes when it was cold. I didnt have time to change the gap tonight but ill try tomorrow. What would cause the car to missfire only when its like 40* or below?

 

[MyBeatGSX]

Do be beat on the car regularly? I drive slower than your grandma and my 7's have a tendancy to foul out in the winter. It seems to be just like you said at <45* when I have the heat on full blast my car has a hard time sustaining temperature (usually hovers in low 170's - high 160's) I make sure to make at least 1 2nd gear pull every time to clean them off a little, this has worked so far.

The local shop told me this is pretty normal for people that drive the cars easy, they said of few people they know of actually carry spare sets of plugs in the car incase they need to be changed out on the road.

 

[JayRolla]

Yea, I baby my car a lot. It sees full boost maybe once a week or less. These are brand new plugs. The first pull I did it missfired at 6k rpm. They are the ngk 6's and I run only 12psi. Its snowing and about 30* now and I hate working in the cold. The funny thing is it did not miss fire with my old plugs and accell wires that where arching.

 

[Defiant]

my ngks are gapped to 0.32 or something like that because thats what the ngk thing recommened to gap at.

That sounds like the N/T gap. Whatever source you got that from, was wrong. Start with .028.

 

[JayRolla]

Actually mitsubishi recomends .032 for our cars Defiant. Just an FYI. We as DSM'rs know thats wrong but thats what they said for the turbo motor.

Well since the weather go warmer my missfire is gone. What the heck? Why would it misfire in the cold only? Any ideas?

 

[Defiant]

Actually mitsubishi recomends .032 for our cars Defiant. Just an FYI. We as DSM'rs know thats wrong but thats what they said for the turbo motor.

Perhaps they corrected when they wrote the Talon books:

 

[JayRolla]

Nice I didnt know that. The mitsubishi dealer ship looked it up and said it was reccomended at .032 the last time I was there. They are such idiots.

 

[Defiant]

Now you're catching on. As you see, they gave you the NT gap. That parts ape may not have known what a turbo is, and thinks you're the dope for believing your car has a Turbo-Hydromatic gearbox.

 

[nightspeed87]

yea they told me 32 also... Do I have to smash them down a little to ungap them?
I also have a 11.1 air fuel ratio instead of the overly rich stock ratio so I imagen my chances of missfiring or fouling the plug is a little less would you agree?

 

[JayRolla]

Yes lower the gap by smashing it a little. Mine is at .028 Defiant. They told me to put it at that but I changed it.