2JZ-GTE missing down low

[PuGZoR]

Hey guys,

Bought a 2JZGTE powered Aristo into the country, and while it's at the compliance shop I decided to start it up and see what it sounds like. Anyway, it sounded like it had a miss, so changed the spark plugs but it still seems to have a slight miss to it. However, this seems to be only up to around 2krpm, where it clears up...

Plugs I put into it are BKR7E's, with 0.8mm gapping.

I'm guessing it might be either a buggered coilpack (that for some reason only works on a good amount of power), crap/old fuel being in the system, blocked injector, or something else. Anyone had a similar problem?

Thanks.

[Draven]

does it idle at normal revs (apart from the miss)? I wouldn't worry about diagnosing till you've swapped fuel (and every other fluid in the car)

[manny]

Plugs I put into it are BKR7E's, with 0.8mm gapping.

Plugs for a standardish 2JZ-GTE are the warmer BKR6E with a 1.1mm gap.
BKR7E will contribute to a miss at idle until the engine is hot.

[PuGZoR]

Yeah, idles easy enough, just has a miss to it. Hmm, alright, will try changing the gap and see how I go. I assume the only difference between the two plugs are that one has a 1.1mm gap and the other a 0.8mm gap, lol. Might run some injector cleaner through the bugger first too, who knows, might clean up something that's formed from sitting idle for the last few months.

[manny]

I assume the only difference between the two plugs are that one has a 1.1mm gap and the other a 0.8mm gap, lol.

Not quite, they are different heat ranges. The number 6 and 7 define the heat range of the NGK plug.
I'd only use a heat range 7 (colder) plug like you've fitted on a somewhat modified 2jz-gte seeing more than 20psi or 250+rwkw - they are known to cause a miss at idle whilst warming up until the engine gets to operating temps.
For a standardish engine running sequential twins, I'd definately stick with the factory heat range 6 plugs.
It may ultimately be another factor in your ignition or fuelling system causing the miss, but having the wrong heat range plug will not help you diagnosing the issue as you're not working from a standard baseline to compare against.

[PlacentaJuan]

yea i am using those iridium plugs with a higher heat range.

the car doesnt like it when its cold and they will miss.

it only takes a few minutes to warm up though.....

[Draven]

FYI: the 1.1mm "standard" gap is crap.. 0.8mm is fine for a standard-mild 2jz, so don't think of that as your problem.

The heat range will cause a *slight* problem at cold temps, but if it's missing as badly as it sounds I'd look elsewhere (or at least wait until it's done compliancing and chaning everything else)

[manny]

FYI: the 1.1mm "standard" gap is crap..

So Toyota who designed, tested, manufactured, sold and warranted the 2JZ-GTE got it all wrong then when they specified a gap of 1.1mm....

[PlacentaJuan]

So Toyota who designed, tested, manufactured, sold and warranted the 2JZ-GTE got it all wrong then when they specified a gap of 1.1mm....

designed as a 206kw engine.

try thinking outside the square.

[brett_celicacoupe]

i run PQ20R toyota platinums.

pretty cheap too. i think i paid $6ea for them last time

http://www.globaldenso.com/PLUG/spec/index.html

[Dieseltrain]

designed as a 206kw engine.

try thinking outside the square.

Hahaha, Manny has tried and tested more spark plugs in his JZ series motors than you could possibly name

[PlacentaJuan]

Hahaha, Manny has tried and tested more spark plugs in his JZ series motors than you could possibly name

why does he sound like such a noob then?

[PuGZoR]

Hmm, I've talked to a few more Aristo owners and yeah, the general consensus is that 0.8mm gap is fine, as long as you're running "low" boost levels and the engine is pretty much stock or mild. This is all good.

The other day we actually got it up to running temp, and it still had a slight miss to it, which leaves me to deduce that it wouldn't be the temp rating of the plugs that is doing this, and that it is indeed likely to be something else. I'm going to do as Draven (and my compliance mate) suggested and wait to worry about the problem when it's gone through the compliancing. It very well could be something simple that could clear itself up so to say, or could be as simple as a wire being lose on a coilpack when I was changing the plugs.

I'll update this thread when I find the problem, might help someone else. Mind you, at this stage, I'm doubting seriously that it's plug related. It's either going to be fuel (possibly even filter), injectors, coils or wiring to the coils, in my opinion. That's my bet!

Thanks for the responses though guys... Funny to see how people can be so divided on stupid $4 spark plugs, lol. But, good to see the different options on the table.

[Dieseltrain]

why does he sound like such a noob then?

Well, his post was justified by the fact that a stock or low boost setup would run fine with 1.1mm gapped plugs, As toyota intended them to be used on those motors from the factory!

He wasnt saying EVERYONE should be using 1.1mm gapped plugs on their motors...

Anyways, good chance it could be a bad batch of fuel if its still an issue once you change plugs.