Jump to content

Spark Plug Gap


180sx
 Share

Recommended Posts

Hi. In another post I asked this question and the OP said 0.044. I was just cusrious to know what everyone else is running. I just replaced my timing belt, so I did my plugs, too. They were all over the place (from 0.032 to 0.063!). The haynes manual says .039 to .043, but it also says only the '98 is to be gapped (I don't know what that's all about). So what are you guys running?

 

On a side note, when I did my t-belt, the original was off. from the LH cam to crank is supposed to have 43 teeth between them, (so the crank is at 5 o'clock), mine had 42 teeth (about 4 o'clock). No wonder my truck had no power below 3100RPM's!

 

Jose

Link to comment
Share on other sites

i can't even feel the plug to put the wire back on, i highly doubt i'd be able to get a new one back there, let alone not cross thread it. i need new ones bad, i've had the truck for 2 years, and the havent been changed yet, and idk how long before i got it.

Link to comment
Share on other sites

jsut curious, how did you do your plugs. i had a hard time just pulling the wires off to pull the valve covers last year. i dont even knwo how to begin to do that rear plug...

 

I just use a 6" extension. It's tight, and I can only rachet about a 1/4 turn at a time from the left so it takes a while, but it works. I just kind of align the socket/extension up with the plug in front of it and it usually goes spot on. I don't know if you still have the tool bag with your Nissan, but Nissan supplied a spark plug tool for this last plug (mine didn't have it).

 

I've always had the habit of gapping new plugs, I usually seem to get at least one or two that aren't anywhere near spec.

 

Well, I should've done that (usually do). When I got the pathy 3 years ago i checked the plugs, and they were all corroded away (I don;t know how it still ran) and the guy gave me new plugs. So I just swapped em out right there (didn't have my gap tool with me). Should've checked them later, but oh well. It's done now.

 

For your WD21 guys, I hear your gaps are larger than us VG33 guys (like .055 or something)(lol, larger gap). Is that true?

 

Jose

Link to comment
Share on other sites

THe 3.0 runs a strong ignition system with an independant coil so gap can be set to .042~.044 The tbi was happy with the big gap.

For whatever reason the 90-95 running the same ignition power (differant mfgr tho) went down to ~.032 this could be due to the MPFI and having an injector right at the valve increases potential to fouling.

Or maybe "1 gap for all models" and the .032 encompases the turbo models in the z31... But they still run when gaped to ~.042

 

The 3.3 runs an integrated igniton system with the coil under the cap. soposedly less energy is lost but peak output is generally lower but not always and for whatever reason the gap goes back up to 0.042~0.044(your answer)

I do not know the ignition power of the 3.3 maybe it is higher,

maybe they decided the risk of fouling was not as great as they thought

maybe 3.3 injectors atomize better so fouling was not a concern

maybe the shorter cam delfects the air stream in way that it mises the plug untill compression

maybe a new set of engineers overlooked whatever reason the mpfi 3.0 had smaller gaps.

 

How many licks does it take to get to the center of a toosie pop?

-the world may never know.

 

\/ For all of you reading my thoughts that just poured onto the keyboard I apologize lol. see the short version below \/

 

No harm will come from running any VG engine at ~0.042 gap.

Gaps grow over time and (somtimes over 0.005)use so air on the short side if you are unsure of your accuracy. How fast they grow depends on use and plug materials.

If you get fouling reduce your gap in 0.005 increments and search for other possible sources of the problem.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...