2JZ firing order

[Norbie]

OK, I've spent several hours this weekend trying to get my goddamn 2JZ started. It chugs and splutters while cranking so I definitely have fuel and spark, but it sounds for all the world like an engine with a couple of plug leads swapped.

This leads me to suspect I screwed up the ignition coil wiring. It's a waste-spark setup and I grouped the coils 1-5, 3-4, 2-6. Is this correct?

I'm pretty sure #1 is firing at about the right time, although my timing light is super dodgy so it's hard to tell. I'm hoping it will be a case of swapping a couple of plugs and it will fire up, I'm losing a lot of hair over this!

[wilbo666]

Firing order is: 1-5-3-6-2-4


Wasted Spark:
1-6, 5-2, 3-4

Cheers
Wilbo

[2jzhilux]

beat me to it

[Norbie]

Farken! I might have known I'd get something arse-about.

So, if I swap #5 and #6 it should all be sweet?

[wilbo666]

So, if I swap #5 and #6 it should all be sweet?

Bzz, John is right

Chees
Wilbo

[Soarer21]

That will get the batching right but not the sequence
Refer to Wilbo's post again and change sequence to suit

[Norbie]

Ah, gotcha. Out with the soldering iron tonight!

[Mos]

Sequencing has already been mentioned, but for reference purposes aftermarket computers generally number their injector and ignition outputs in firing order rather than cylinder order, in contrast to factory computers that number outputs in cylinder order. That is, output 1 is the 1st firing event, output 2 is the second firing event (regardless of which cylinder that happens to be), output 3 is the third firing event, etc.

In your case it doesn't matter, because no1 (and no6) gets fired first, no5 (and no2) gets fired second, no3 (and no4) gets fired third, but if you were individually firing each cylinder then you would need to address sequencing (ie output1 -> no1, output2 -> no5, output3 -> no3, output4 -> no6, output5 -> no2, output6 -> no4, assuming 1-5-3-6-2-4 firing order).

BTW exactly the same philosophy follows for injector outputs...

Mos.

[Norbie]

In your case it doesn't matter, because no1 (and no6) gets fired first, no5 (and no2) gets fired second, no3 (and no4) gets fired third

Ah, I'm pretty sure that's how I've got it wired up but I'll double-check tonight. Thanks Mos.

[takai]

Sequencing has already been mentioned, but for reference purposes aftermarket computers generally number their injector and ignition outputs in firing order rather than cylinder order, in contrast to factory computers that number outputs in cylinder order. That is, output 1 is the 1st firing event, output 2 is the second firing event (regardless of which cylinder that happens to be), output 3 is the third firing event, etc.

In your case it doesn't matter, because no1 (and no6) gets fired first, no5 (and no2) gets fired second, no3 (and no4) gets fired third, but if you were individually firing each cylinder then you would need to address sequencing (ie output1 -> no1, output2 -> no5, output3 -> no3, output4 -> no6, output5 -> no2, output6 -> no4, assuming 1-5-3-6-2-4 firing order).

BTW exactly the same philosophy follows for injector outputs...

Mos.

I got reamed by that a while back, very annoying.

[Norbie]

OK so I swapped #5 and #6, this improved matters significantly but something is still not right. I'm thinking the grouping is right but the firing order is wrong, but I didn't get a chance to check it.

[The Real Roadrunner]

swap the coil triggers from coils 2-5 and 3-4. this should solve your problem and get your 2jznoshit running like a fat kid to a cake sale.

[Norbie]

Yep, already done that and things improved dramatically. It still doesn't quite want to start, but it's definitely close. I suspect I'm getting an erratic signal from the CAS, no doubt due to the temporary nature of the CAS wiring at the moment. I'm going to buy a decent timing light on the weekend and hopefully that will tell me what's going on.

[The Witzl]

i've been reamed by the same "firing order" instead of cylinder order on aftermarket computers.... i felt so stupid.

Get wilbo to bring over a CRO too... to make sure you ahve the CAS wiring correct.

[Norbie]

Victory is mine! I ran all new shielded cable from both sensors all the way to the ECU and it fired up easily and ran reasonably well. Still a bit rough but I suspect the AFR's are way out of whack. Tomorrow I'm putting the cooling system back together and I'll have a closer look at that.

I'm so glad I got this sorted, I was ready to torch the thing to the ground! Thanks for the help guys.