Ali SC3

iTrader: (10)

Hey man, Its been a minute, hope all is well. The sequential system is the superior system in terms of performance, but not in complexity, reliability or emissions.
Part of the reason the 2JZ was discontinued was the inability to meet emissions in later years because it was performance oriented design having the Toyota "G" designation that means aggressive valve angles in the cylinder head. The 2JZ does alot of things well but being low on emissions was not one of them.
As I am writing this I just realized you probably know all of this info already but I am sure some others don't.

Remember the 2jz-fse? that was the final attempt to make things burn more efficiently giving it an "F" designation that means narrow valve angles in the cylinder head to promote a cleaner burn.
Toyota also used direct injection and 11+ compression on that motor, and it worked very well but was not popular due to not being very modifiable or performance friendly and thus the end of the mighty 2J.

I think on the gte vvti it was a band-aid on the problem emission wise cause they don't make turbo "F" motors or turbo direct injection at least at the time.
My guess was it was a design choice also used on the ge vvti for the same reason which I also think is another reason they did not need EGR.
I would guess it was part reliability (the 6 gte coils were always problematic), and part for a more complete burn.
There is some argument over whether firing on the exhaust stroke can cause exhaust to make it back into the intake slightly, I am not convinced it is a strong enough effect to change directions of the general airflow but for arguments sake lets say that if it did even slightly it would also act like an egr type process... which to me sounds like it would further reduce emissions and promote a cleaner burn.
Maybe another reason no vvti's have egr in addition to the vvti action mimicking egr as well, arguably both mechanisms could work together by adjusting the duration while firing through the exhaust cycle to promote the change in direction.

It makes some sense in my head but I would like to test it to be sure and I don't really have a way to do that an emissions monitoring dynameter.
There is probably an Engineer somewhere who knows why exactly they did it, maybe if we send Mr. Toyoda a nice email he might let us know some day.
Until then we will all be guessing, who knows maybe they did it just cause they had extra ge vvti coils sitting around =)

Curiously enough there were plenty of "F" motors produced at the time with modern sequential coil-packs with the built in ignitors which reduced complexity.
So by elimination that leaves reliability and/or emissions as the only reasonable choices left as to why they didn't use 1ZZ-fe, 1uz-fe or 1MZ-fe type COP for the gte vvti.
Is it coincidence that all of those late 90s engines that got sequential COP are fe's that already have good emissions.. I would say a definite maybe not lol

If the boots are good they pretty much click onto the plugs and sit there with a little lean back. Once you put in the other 3 plug tubes behind them and the wires it sort of wedges them in place.
I have seen people also use those very little silicone stick on spacers for like furniture on each side of the coil so it wedges against the sides of the valley, that would help alot to keep them still.
Some make fancy brackets for it if you feel the need to go the distance. I just drop them in there and start slamming gears, haven't had one pop out yet and I don't even use the plastic spacers or anything.

bbyatv

Ali,

Thanks for getting back. I will see how they sit in there and accommodate accordingly.

Bruce

bbyatv

Hi Ali. So I got the vvti coils in and the car runs ok. It was an easy upgrade for the most part. I opened the plugs back up to .032. The car runs better, but I am still getting a stumble at times. I am wondering if I have something going on with my O2 sensor? Or maybe I need to close the plugs down a bit? If I start from a stop and run through the gears hard, that is when I get the least amount of stumble (but I still get some). It is better than before COP. When I am running down the road in say 3rd or 4th gear and give it hard gas, that is when I get the most stumble.


This stumble has been perplexing me for so long. I feel like I have tried everything. Maybe the O2 sensor? Any thoughts? Also, my AEM AFR gauge went full lean. Not sure if that is helpful or just coincidence. I am not sure why it went full lean. Maybe a bad O2 sensor? Just not sure. The O2 sensor to the ECU is a 4 wire and the AEM is a 5 wire.

Also, the vvti coils cam off a 2002 Lexus GS300 Sport Design JZS160 with 182,358 miles. Maybe the coils are weak?


Thanks,
Bruce

Thanks,
Bruce

Ali SC3

iTrader: (10)

I would check where the map sensor is getting its source from is a nice short line. that one is a tough one, maybe a small leak somewhere in the IC piping? check all the clamps under the car. Probably not the coils if its on tip in while in gear. could be related to a lazy o2 but when you are full throttle it shouldn't be there then.

bbyatv

Hi Ali,

So I went through the car with a fine tooth comb. I found a vacuum leak at the blow off valve and I found that the O2 sensor on the AFR gauge was bad. No leak in the IC plumbing. I pressure tested it.

So after fixing the vacuum leak and replacing the O2 sensor, I have nearly got it. The car runs real solid and the AFR works again. I still get a very, very slight stumble. I am going to take the plug gaps down from .032 to .028 and see if I finally have it nailed.

Thanks for all your help,
Bruce

Ali SC3

iTrader: (10)

Sounds like it should be all working well now, you can see if that helps out any. If its swinging too rich on tip in or staying too rich in boost, it could be possible your injectors are flowing a little too much for your setup.
You could dial it in with an afc or similar by removing one percentage across the board like 5% out etc.. You are running 440s right?

bbyatv

Hi Ali,

Thanks for the feedback. Yup. I am running Bosch 440cc. I was wondering if I might be dumping too much fuel into the cylinders. I assume an AFC is a fuel controller of some sort. I am not familiar with them. Is there one that you are familiar with that you could recommend in the event I go down that path? I will watch my AFR and see how rich it is at tip in and full boost.

Thanks,
Bruce

KahnBB6

iTrader: (5)

It has been a while yes! I've been consumed with a lot lately and am just on the mend from a minor surgery I had this week but I'm all good. I hope things are going well with you! : )

This was my initial guess-- that the sequential firing system was an early implementation for performance reasons. When the JZ series was first designed it had an easier time with emissions requirements (and average fuel costs!) and things only got tighter and harder for its design to cope with as the 1990's pushed forward. The aggressive valve angle "G" cylinder heads across the Toyota lineup back then were always the best for racing purposes. Different era.

I absolutely do. I looked into the 2JZ-FSE for a bit until it was beyond apparent that there is no aftermarket support for it despite it having a dual VVT-i cylinder head. The compression ratio could have been changed but tuning options for its direct injection system with an aftermarket standalone ECU haven't even been available for years... and a few risk takers seem to have already determined what you have said: that the narrow valve angle head just isn't good for making extra power with a turbo versus any of the older 1JZ and 2JZ engines with "G" heads.

It's a shame that Toyota could do for the JZ series what General Motors was able to do for their long running LSx engine series which are only just now starting to be phased out for good after the Camaro and Cadillac CT5V models go away.

^^ VVT-i was definitely the reason that traditional EGR was no longer needed but your theory as to why the 3 coil wasted spark system was a compromise for emissions purposes is very interesting.

Yet you say that the 6 coil pack sequential fire ignition system in the 2JZ-GTE Non-VVT-i (1JZ-GTE Non-VVT-i's used 6 coil packs but in batch fire) was always problematic.

I am curious as to why you feel the sequential fire 6 coil system was/is problematic. I've had a few unique troubles of my own with mine but I am mostly sure that was primarily becasue I was missing a crucial factory ground at the back of my cylinder head (as you'll recall when I was constantly diagnosing the issue).

Are you referring to general age of the coil packs when they get cracked and require repairs? Or are you referring to the IGF firing signal handshake between the Non-VVT-i coil packs, igniter unit and increasingly old factory ECUs?

None of us have such expensive equipment of course! ; ) I think the only person here who might know anyone who can still tell us why the switch from sequential fire 6-coil and batch fire 6-coil to wasted spark 3-coil ignition systems were made to the 2JZ-GTE VVT-i (and 1JZ-GTE VVT-i as well I think) would be Yamae, who used to work as an ECU engineer for Toyota back in the day. Occasionally he's been able to provide us with some details as to why certain things were done electrically in Toyota engineering in the 90's.

This is a very good point ^^. I think it still comes back to, as you say, the JZ series being designed primarily as a performance/racing engine design directly intended to compete with Nissan's RB20DET, RB25DET and RB26DETT power-plants. Emissions were easier to meet in 1990-1991 when it first debuted and with each passing year the various tricks the engineers could use on it to squeak by emissions requirements yielded diminishing results up until the 2JZ-GTE VVT-i manual version was retired in 2002 followed by the Aristo auto-only version being retired after 2004. The 1JZ-GTE VVT-i lived on for a few more years... until 2009 or so if I recall.

Those other "FE" head engines had less emissions to manage with the lack of turbocharging but I think the real truth is that they were just far newer cylinder head and engine block designs when compared to a base architecture from 1990. The 1JZ-FSE and 2JZ-FSE heads were interesting fuel economy only efforts but they also had to conform to what was still a performance engine block design from 1990.

Ali SC3

iTrader: (10)

Yeah let us know what the cold start afrs are and the temp outside when you start it.
When you are in closed loop when you first press on the throttle it will swing rich, see if you can make note of how rich it is.
That might be where the issue is if you are swinging more than a 12 on tip in.
And of course your full boost afr and what psi that is at.
Its hard to tell if you need to pull some fuel out sometimes as these ecus tend to run rich anyways out of closed loop, but could be the issue not all 440s flow the same.
Maybe see if it learns some after a few drives.

You would just need any basic safc or similar from that area and they are simple to install.
Could try and remove 5% or so across the board (reset the ecu) and see the change in afrs after it learns some and if it helps or not.

Hope you recover well, all is good just doing the usual stuff.
I would really like to play with that dual vvti cylinder head!! too bad it isn't a ge or gte head or I am sure they would have ended up on some builds by now.
The gte ignitors have issues here and there as I think you experienced, they get super hot, and the coils tend to have those cracking issues along the stem.
If you have a set in good condition they do spark better than the vvti coils but not by a huge amount. Both are night and day compared to the single coil setup.

But unless they are already on your engine (you gte guys lol) the cost of finding a good condition set with an ignitor and tackling all that wiring is a little daunting.
If you have to wire in sequential coils starting from scratch most are going to be choosing the newer self ignitor ones like the 1zz, it cuts the wiring in half and no hot ignitor to hide.

It seems BMW continued innovating along the inline 6 turbo path after Toyota moved on, I would guess that is also part of the reason the new supra is the way it is.
The 2JZ and the old BMW motors had some similarities, you can bolt a e36/46 clutch up to a 2jz supposedly... I would like to see Toyota take another round at a performance yet emissions friendly-ish 3JZ.

fll2atl

Ali,

I hope all is well. Im in the NA-t process and wanted to get you input which vacuum route would you suggest after the egr delete?

Thanks in advance





h

Ali SC3

iTrader: (10)

The first one is close but the canister in the top left is your charcoal canister for the fuel tank and should be kept generally unless you like gas smells or know how to delete it properly. I'm not going to cover that here since most people should keep it. The one line that comes from it goes to a tee, one side goes to a check valve and then to a port on the top of the throttle body (mechanical side opens under part throttle), then the other side of the tee has a vsv then back to a different throttle body spot (not ported, this one is so the ECU can vent the canister outside of part throttle).

If you ditch the stock ecu, you can remove the vsv side of the tee, but keep the line with the check valve running to the top of the throttle body. At least you will have some venting of the canister that way.

Most definitely keep the one line to the fuel pressure regulator at the bottom.

If you have the acis butterfly valve in the intake still keep the blue part in the middle also. If you are off the stock ge ecu remove the vsv and vacuum tank and connect the acis actuator straight to manifold vacuum.

So if you are on the stock ecu or a gte ECU, just the EGR stuff goes if it's removed, leave the rest in place you want all that other stuff.
gte ECU or standalone you remove the acis vacuum canister and vsv, GE ECU you can leave it.

kyndaleDhowell

I’m getting ready to buy all the necessary things to turbo the car just wanna double make sure i have everything correct I’m going with an aristo for my 95 5 speed and was wondering if wiring in the 02 is a must. Also I’ll be buying the cx racing kit and I’m a little confused as to where I will place the oil line into the pan, do I need to drill a hole in the pan or have it welded onto the pan. My biggest issue is I only have a weekend to do this and don’t wanna be missing anything or have something come up, because of a fault of my own. Thank you in advance!

bbyatv

I installed a CXRacing kit on my 95 5 speed. Here are few link that might help with your install.
As I recall, I think I drilled and tapped the block for the oil return.

https://www.clublexus.com/forums/bui...w58-build.html

https://drive.google.com/drive/folde...F2?usp=sharing

Bruce

fll2atl

Hi Ali, I recently picked up the AeM V2 6100. Do you know if the wiring for this box is the same as 2jzgte ecu mod? My only concern is I'm still running the dizzy & don't want to damage my engine on the first start up. Let me know your thoughts & thanks in advance!

Ali SC3

iTrader: (10)

The AEM V1 and V2 can run the stock ignitor and coil without any changes. The wiring above is only needed for the oem GTE ecu because it looks for the newer IGF signal that is returned from the newer ignitor (TT or ds62/dh61).
The AEM ignores the IGF signal so it does not care what ignitor or ignition system you have. Just follow the settings for the Non turbo box it should already be setup for the stock coil with the stock single IGT wire going to the ecu.