nsjuice

Found some info in regards to my questions about ECU SUPRA/ARISTO Part ID numbers. If anyone has a bigger database, feel free to add please. http://www.supraforums.com/forum/sho...cation-Numbers

Ali SC3

iTrader: (10)

Yeah there are a few threads where its discussed, I just haven't done it before. it should work though with the right resistor in theory.

If you have a supra ecu whether its auto or manual 6spd, it does not need the a/c relay fix.
The supra has the same style a/c unit control as the sc300 well cause they are practically the same car electronics wise.

The only ecu that needs the a/c relay fix is the aristo ecu cause its a different chassis

Aristo ECU Part Number:
- 89661-35060 (91-93)
- 89661-30870 (93-97)

Supra ECU Part Numbers (Auto, J-Spec, NA):
- 89661-14600 (93-97)
- 89661-14810 (97-99)

Supra ECU Part Numbers (Auto, J-Spec, TT):
- 89661-14490 (9305-9310)
- 89661-14491 (9310-9605)

Supra ECU Part Numbers (5Spd, J-Spec, NA):
- 89661-14610 (only number listed)

Supra ECU Part Numbers (6Spd, J-Spec, TT):
- 89661-14500 (9305-9310)
- 89661-14501 (9310-9605)
- 89661-14770 (9605-9709)
- 89661-14830 (9709-)

Supra ECU Part Numbers (6-speed, US Spec, TT):
- 89661-14520 (93.5-95)

Aristo ECU (JZS16#)
- 89661-3A470 (9708-0007)
- 89666-30180 (0007-)

The ECU part number depends on the age of the car.
2JZ-GTE engine
jzs=Aristo
89661-30510 = JZS147..Q Oct 91 - Aug 93
89661-30750 = JZS147..Q Aug 93 - Aug 95
89661-30880 = JZS147..Q Jul 94 - Feb 95
89661-3A180 = JZS147..Q Aug 95 on

2JZ-GTE engine
89661-30560 = JZS147..V Oct 91 - Aug 93
89661-30870 = JZS147..V Aug 93 on

SC300T

I'm installing the AEM EMS V2 into my 92 SC300... I've got this weird problem with the MAP sensor reading wrong. On the screen of the AEM, I'm reading over 5 volts when the engine is off. MAP SENSOR ERROR ON. Its as though the EMS is reading a max signal from the sensor. As part of the install, I've clipped the wire from 66B (MAF) as seen in the pic directly in front of my thumb. This is the yellow green wire at the bottom center of the connector. I've moved this wire to an orange wire to the right bottom, the one prominently in the pic. This is wired to 62B. I've checked the voltage running on this orange wire and it reads 1.6v. I have no idea why the EMS is reading 5 volts. Anyone have any ideas? I'm stuck at this point. I'm runing the 3.5 bar AEM MAP sensor. When I measure voltage at the sensor, I get the normal 5v from the power lead to ground, and I also get 1.6v from the green signal lead to ground, so I think the sensor is working. In the wizard, I've setup 3.5 BAR AEM MAP sensor and it seems to match up fine. I've also verified that the orange wire has continuity to the pin on the back of the connector. Even with the orange wire disconnected, it still reads 5v. Any help is appreciated. Thanks.

SC300T

Found the issue.... Apparently if the ECU doesn't see a signal it reports it as 5v. I re-pinned the orange wire in the pic and tried it again and it worked... Still cannot get the car to start. Stat SYNC will not turn on. Running MSD 6BTM ignition amplifier so I'm sure that doesn't help. Any ideas to get Stat Sync to turn on? Below is the pic of cam/crank settings.

Ali SC3

iTrader: (10)

yeah I was going to say sounds like its not plugged in all the way or something, aem will default to max or min depending on how its set when it doesn't see the signal.

what is the "crank falling edge" set to? I can only see the value for cam 2 on the third window from the left at the top.
it should be falling edge on, and rising edge off for the crank and both cam sensors. you might need to try and set the timing if you have to change that value.
but stat sync indicates that something is off between cam and crank sensors, or signal is not strong enough.
sometimes you have to charge the battery up fully for those to pick up correctly.

you can also try changing the "Crank H sens below" from 500 to 2000, and the "Crank L sens above" from 500 to 1900, sometimes that helps with the distributor.

also what seems weird, is that your load is reading -14.7 psi? with the engine off? that isn't right it should be around 0 with the motor off so your map sensor may not be set up properly still unless that is an older picture before you fixed it.
Map sensor reading wrong wont change getting stat sync'd or not, but once you get stat syncd it will affect how it runs as soon as it turns over.

SC300T

The crank rising and falling edge are as you mention above. Also tried Crank H settings above, no change. Battery is new, cranks FAST, no ECU interruptions or lack of current.
Timing in indicator window is -17 degrees. Seems odd? But would it affect Stat Sync?

gerrb

iTrader: (34)

Ali - do 2jzGE pre VVTi pistons have exactly same compression as the 2jzGE VVTi pistons ?

You probably know why I am asking that question and where I am heading to on this...... SC300 non VVTi have a compression of 10:1 while SC300 VVTi are 10.5:1 . What makes the difference ? Is it on the piston compression rating ? If it is then swapping a VVTi head to a pre 98 block will bring you back to 10:1 since you are now using pistons with 10:1 compression ?

Or is it the recess on the VVTi and non VVTi heads that spells the difference in compression and pistons have same compression ? Based on what I have read so far , both vvti and non vvti head both have a recess of .025" . Any idea or confirmation on this ?

Just very curious now though I know I will be able to confirm how pistons and head looks on both when I disassemble engines from those two cars.

Ali SC3

iTrader: (10)

that will be under the start settings you can change the timing value, but until you get stat sync nothing happens.
once yuo get stat sync it will do the injector crank pulse of fuel for starting, and then it will use the timing in that box on the start page.
once it turns over and crosses starting rpm's then it will reference the main fuel and timing maps, and usually is when it will fall on its face until you tune that stuff, but for starting you need to get stat syncd before anything else.

monitor "timing errors", and see if you get a bunch of those. I have seen some distributors where the ems would not pick them up at all until another one was put in there, not saying that is your issue but it can happen. they aren't adjustable and the stock ecu's are much better at picking up the distributor's analog signals then the aftermarket ecu's are, so its something to think of as a last resort. really all it needs to get stat syncd is a clean crank signal and a clean cam signal, so you pretty much know its the distributor, the wiring, or the aem box itself.


That is a good question, I am not 100% sure but I think the pistons have similar or the same volume from non vvti to vvti, but there is the whole ringland difference. of course.

From research I have found these different measurements, the non vvti are fairly well documented, but the ge vvti I am not positive but again what I found and it makes sense if pistons are similar CC.
GTE non vvti head volume is ~45cc (from the supra piston thread in n/a section)
GE non vvti head volume is ~ 44.2cc (could even be 45 same as gte not positive this is from the supra piston thread in n/a section)
GE VVTI head volume is ~ 41.6cc (from IS forums)

So when looking at those numbers it seem like the extra .5 compression is coming from mostly the cylinder head, maybe a hair from the pistons but more likely just the measurements are off a little.
from some of the numbers in the non vvti compression ratio calculations very roughly you can take the CC amount and multiply it by 0.13 to find your change in compression ratio.

so lets say the GE is 45cc cause I think its actually closer to being the same a gte head, and the ge vvti is 41.6cc (a leap of faith here trusting this number but lets see).
So you would have 3.4cc * 0.13 = you would have a .44:1 change in compression ratio.
That is pretty close to the stated .5 change in compression ratio so I think its coming mostly from the head if the numbers are even semi accurate.
even if a little is coming from the pistons and the measurements are off in the wrong direction, the head is definitely upping the compression ratio some cause there is a stated CC difference.
So you are safe to assume the compression ratio will generally go up a bit with the vvti head.

its hard to tell exactly the CC's on these heads just by looking at them, like the GE head has a .030" recess and the GTE does not...
but what brings them both back to the same CC is the GTE valves are more aggressively angled so it creates more volume to make up for the lack of recess.
so you can't just compare the recesses, you have to note the valve angles and height of the compression chamber etc... well that is my basic understanding of the differences hope that helps.

I am very curious to see some pics of them side by side once you do open them up, I haven't seen a good side by side of either the pistons or the cylinder heads that would be very helpful.
who knows might even get a few surprises from what I have researched cause nothing is as good as seeing for yourself these days.

I remember when Omar threw a ge vvti head on an non vvti block with a stock ge headgasket, that thing felt like it was higher compression than normal to me cause at the time my na-t was on stock 10:1 compression, I think his compression numbers were also coming out on the high side. I want to say he also blew the headgasket the week after putting it together when it overboosted some, which probably wouldn't have happened if it was lower compression. this was the one that put down a little over 700hp but he had a machined gte cam in there so vvti was deleted. I remember we couldn't get the thing to start and we thought it was all messed up from the Frankenstein combo until we figured out the crank sensor wires were reversed (it was a non vvti ge block/harness so everything was added from scratch including the wiring), so swapped them out and it fired up and it just purred, well violently loud cause of the open downpipe but it was a happy motor to say the least.

gerrb

iTrader: (34)

Yeah ... we will find out when I disassemble both engines . Going through some vvti and non vvti pistons on the internet , I have the feeling that the pistons play some role on the compression that brought up the VVTi compression ratio to 10.5:1 aside from the volume of the head itself . The vvti and non vvti do not seem to have same compression or displacement / cc .

look at these :

2jzge non vvti piston (from SF thread)


2jzge vvti piston from an is300 , gs300 , sc300 (from ebay auction)

gerrb

iTrader: (34)

Been doing a lot of NA-T components research lately so I can do my NA-T side project right the first time , here is another set of 2jzGE non vvti and 2jzGE vvti pistons which now makes me believe that the pistons do play a good role on the compression bump of the VVTi . There seems to be a big difference on their CCs .. not unless my eyes are deceiving me .

As mentioned on SF, the squish band on the vvti is carried all the way around the piston which includes the exhaust side and it only take 2.93cc to go from 10 to 10.5:1 . I know , as you have mentioned , and as I have read also vvti head volume is smaller. This makes it a bit murky and me confused all the more . I want to do this thing right the first time ! I just realized I already have an opened GE short block taken out from a running MKIV that already has ARP rod bolts and ARP mains in my garage which I prepped a year or two ago and documented on my build thread. So the question remains , will I keep the 10.5:1 with non vvti short block ? If I won't then there is no point of opening my 38k miles engine. Just preserve it for something else . Go get stronger pistons and rods for my opened 2jzGE MKIV block that will enable me to keep 10.5:1 compression and have stronger internals. But that defeats my purpose on this NA-T side project... using as much stock components possible to maintain the 10.5:1 compression and get into the 500-600rwhp with VVTi provided it doesn't compromise reliability. And I know the the VVTi short block won't make it due to weaker rods and piston / ring designs.

Well , seeing both heads and pistons in my hands when I disassemble the vvti engine will give me a better idea of real differences.

KahnBB6

iTrader: (5)

Ali, I'm just catching up on this thread and seeing all of these ECU part numbers listed, would you mind if I include them in the ECU part number thread I made a while back? It might be very useful to have not just SC300 and SC400 ECU part numbers in that thread but also the many common 2JZGTE ECUs we commonly swap to.

This one: https://www.clublexus.com/forums/per...s-by-year.html

Ali SC3

iTrader: (10)

those pistons look pretty similar, maybe its making up that last .15:1 compression... haha it really seems like guesswork but you will have a high compression setup no doubt about that. I think you can hit 600 all day long, you should shoot for another 800-1k motor =)

Kahn I copied and pasted that from another thread so feel free to copy it again.

KahnBB6

iTrader: (5)

Thanks Ali!!

nsjuice

I realized that originally, 440cc injectors were called for the mod. But realized that I'm going to go stock ignition with distributor. Saw HiPsi post about getting 550s for that setup. Am i screwed for having purchased 440cc?


Also, I just realized HiPsi had everything wired without a turbo kit!? Safe enough to run without one for a while, I'm assuming?

SC300T

Still getting no Stat Sync - No start on Lexus SC300 NA-T with AEM EMS.
Brief background... Trying to install an AEM EMS v2 into a 92 SC300. Originally had MSD 6BTM ignition box which we thought could have been causing the AEM to not stat sync. As a test, I returned the car to stock ignition, and tested---- The car starts and runs with the OEM ECU. As soon as AEM V2 is installed, it will not sync. There are cam counts, but no crank counts, which is surprising since car runs fine on stock ECU. My next step is to see what pins the crank counts would be registered on in the ECU and try to trace that back and see if there is a signal. According to the Lexus repair manual, the ECU is looking for a +5v / -5v pulse on crank. I suppose my next course may be to look at the crank signal on the ECU pins to see if I'm getting the correct pulse. Thinking of buying a PC attached Oscilloscope to look for this waveform. I know its getting pretty technical, but I don't know where else to turn as I'm in Cincinnati OH, and don't have a shop that I know of that has extensive 2JZ + AEM experience. I suppose I could also look at the distributor and the air gap between the sensor and the rotor. Looking for ideas... Anyone? I posted on AEM forums and a tech suggested returning the ignition system to stock, which did not change anything.