[mafbxh]

Hi, everyone,

This is a great site and I have done all my oil change, grease the nip, changed the differentiate oil, and changed the filters all by instructions on this site.

now my 2008 FJ reached 30000 miles, I changed my spark plug last week with NGK laser irdium 4904 from amazon.

I followed the instruction on this site and the youtube and used a torque rench to torque it to the right torque. The battery also disconnected during installation process.

everything seems fine after change, it look like the engine has more power.
but I get the worse MPG ever, 12MPG in the first full tank after the change.
normally it will have 16-19MPG.....

is the computer in FJ still learning the new spark plugs?

it should have better MPG as I imagine.....


any ideals?

 

[Apexbasher]

Were they gapped correctly? Did you get some crappy fuel?

 

[1911]

Make sure every coil tower is firmly and positively connected to the harness. Like Apex said, they all need to be gapped to 0.040 inches. If those are both good, then it is probably the tank of gas (winter blend, ethanol, etc.).

 

[mafbxh]

thanks Apex and 1911,

I am still running the second tank, it looks a little better, get about 80 miles while the meter shows about still have 3/4 tank, I will check the second tank for MPG.

For the wire and harness, I think it is quite tight, I hear the click for every one when put it on.

For NGK irudim spark plug, the autozone guy who sells me the gap meter tells me they dont need gap, and on the box, it is showing no gap allowed by some picture. I did not check them. if it still have bad MPG, I may take them out and check again.

by the way, NGK irudim spark plug do not allow anti seize grease to be used. it is showing on their web site.

thanks again

 

[cmaj7]

Amazing how many folks buy iridium or titanium thinking they are getting a "better plug". These plugs last longer but at the sacrifice of some spark, copper is a much better conductor than either of these two materials. Many high performance shops specifically spec out copper plugs that run one or two steps cooler than OEM. Iridium and Platinum are great if you only want to change your plugs twice in the lifetime of your car. If you are looking for better performing plugs, you really can't beat copper. The drawback is that you have to change them every 30k - 40k.

 

[1911]

Amazing how many folks buy iridium or titanium thinking they are getting a "better plug". These plugs last longer but at the sacrifice of some spark, copper is a much better conductor than either of these two materials. Many high performance shops specifically spec out copper plugs that run one or two steps cooler than OEM. Iridium and Platinum are great if you only want to change your plugs twice in the lifetime of your car. If you are looking for better performing plugs, you really can't beat copper. The drawback is that you have to change them every 30k - 40k.

Absolutely true; that is one reason of many why I only run plain old stock copper Denso plugs in all my Japanese vehicles.

 

[gsd2053]

is the computer in FJ still learning the new spark plugs?

Please try Lukas gas upper cylinder Lube. I swear it will increase your MPG in the FJ. More than it costs. I have only seen a big difference in MPG in the FJ with this stuff. However it is great.

 

[nativejim]

is the computer in FJ still learning the new spark plugs?

Please try Lukas gas upper cylinder Lube. I swear it will increase your MPG in the FJ. More than it costs. I have only seen a big difference in MPG in the FJ with this stuff. However it is great.

do ya use this at every fill up? just wondering....