Standalone ECU AEM EMS driving UZ's

[SuperRunner]

what did you do about the igniters? Just use Supra NA igniters?

Any pin swapping to get the thing to fire up, or is it mostly plug/play with exception of 2 additional injector wires.

 

[MitchP]

Tranny shifting is way different and much improved. I can program which gear I want to be in based off TPS and Vehicle speed and am still tuning it in but it feels pretty good. I've got it so it doesn't do the stupid quick shift out of first at light/moderate throttle that annoyed the crap out of me. The other weird factory shift programming is gone and it actually does what I want it to do. No shifting frustrations here.

Shifts are firm and quick, but not harsh. You can control line pressure and the lockup of the torque converter. I'm not sure what effect it will have on the longevity of a tranny with 215K+ miles on it but I will find out. (trannys are relatively cheep if it does go, err, I mean, when???) I have put about 200 pretty hard miles on it with no ill effects yet other than maybe less tread on my rear tires. I will keep you guys updated if the tranny launches it cookies or anything.

It truly feels like driving a different car and is really hard to explain in words where one ride/drive in the car can explain so much.

I do some very minor mods to the AEM EMS for the coil signals and some other minor stuff. Added in a MAP sensor and dual widebands to make tuning a snap, otherwise using all factory everything with NO pin swapping needed on my car.

On a 92-95 car, the injectors are batch fired off 4 pins so no pin swapping is needed and they are paired up two per bank so bank to bank O2 control is possible, although I've found each bank is pretty close to the other in stock form.

Could go back to stock ECU in 5 minutes which will be handy for back to back testing when I go to the dyno here in a couple weeks. Stay Tuned.

 

[MitchP]

Here's some video's from the SC this morning.

This first one is cold startup.

http://www.youtube.com/watch?v=09Kde5jWhsU

The second one is a WOT downshift. (sorry it's shaky)

http://www.youtube.com/watch?v=n37w85jSZms

Enjoy!

 

[cribbj]

Pretty nice there Mitch; the engine sounded smooth and the AFR's looked great.

It sounds like a different beast than a regular SC400. Even naturally aspirated, I'll bet you can still surprise quite a few people from a red light or from a roll.

 

[MitchP]

Thanks John,

I'm really happy with how the car sounds and most of what you are hearing is from the custom 3.5" aluminum cold air intake I made for it. It's pretty loud when I put my foot in it. I have surprised quite a few people, as not a many people expect an SC400 to sound like that.

I have also replaced the two rear mufflers with 2.25" aluminum straight pipes from the axle flanges back. It gives a nice low rumble at idle and light throttle but isn't excessively loud. At freeway cruising speeds, you can barely notice it so driving long distances doesn't tax the eardrums.

Update on the AEM EMS: I have put about 1000 miles on the car, driving it everyday to and from home, tuning appointments, and the shop. Gas mileage has been about the same as stock over the last couple tanks. I had some stalling issues early on but those are now solved. Getting the idle motor control perfect with an automatic is bit more tricky than with a manual. Also had some issues with the Decel Fuel Cutoff coming in a out a bit at certain points causing a slight lurch at some points but got that taken care of. Still need to find time to get to the dyno though. Hopefully some time this week.

I have the line pressure turned all the way up except for very low throttle angles and it feels really good. I've got the Gear Desired Table and Torque Converter Lock Up tables dialed in a little better now but still not 100% right. There are still some places where it downshifts 2 gears where maybe only going down one would be better - maybe setup a bit too aggressive right now.

Next thing to work on is dialing in the upshift timing retard/cut so the upshifts are quicker and puts less stress on the transmission as it won't have to pull down the engine speed with it going at full power. Right now my 2-3 upshift takes about 380-400 mSec without any timing retard or ignition cut. I'd like to see how quick I can get it down to just through tuning. Will keep you guys updated.

 

[SuperRunner]

can you share your cal file? I am installing my AEM in my SC400 right now.

 

[MitchP]

Sure I can. I'll try to find time tomorrow to pull the calibration out of the car and post it up. Keep in mind you'll have to use it at your own risk and I wouldn't recommend driving the car aggressively until you get it to a dyno and properly tuned.

EMS related, my car is completely stock except for an AEM Dual Channel UEGO controller and an AEM 3.5bar MAP sensor. If you have a different setup (Injectors, UEGO, MAP sensor, TPS, etc...) let me know and I can change the calibration around for that stuff.

 

[SuperRunner]

I am using 2JZGE igniters, and of course a supercharger.

So far I have been dealing with the ignition stuff. It seams the coils just aren't firing correctly. They only fire once per rotation instead of 4. I think once I get that figured out, it will be running just fine. Might have something to do with low voltage though and the sensitivity of the cam sensor pickup. The battery is charging right now(pretty dead), so maybe I will have better luck in the morning.

 

[SuperRunner]

So I got it running, but I am not sure if the coils are firing correctly.

It think it is possible they are firing twice.

Something that I had to do was set the fuel teeth to 24 and spark to 4. It did not run at 24 and 24.

It idles ok, but doesn't sound as smooth as it shold be. As soon as I take up the RPM's though it sounds great.

 

[MitchP]

For early cars that are batch injected, you'll want the fuel teeth to be 12 so all four or outputs fire once per rotation instead of once per cycle, if you have 24 fuel teeth.

You'll want to set spark teeth to 6 so that each coil output fires 4 times per engine cycle.

I will post my cal up here shortly.

 

[SuperRunner]

Right now I have mine set at 24/4. At higher RPM's it seems to do ok.

So you say 12/6 is the proper setting?

Did you do anything for the pickups? I noticed that if I don't have an absolute FULL charge on the battery, I will not pick up an RPM signal.

 

[MitchP]

See the attached calibration file. Use at your own risk.

My car is a '92 and I have around 4,000 miles on my car using this calibration. I have a 3.5bar AEM MAP sensor (plumbed to the PS manifold port) and AEM Dual UEGO controller. Everything else is stock. Fuel table is TPS & RPM based with MAP sensor fuel correction and ignition table is MAP & RPM based.

12 and 6 are the correct settings.

With 12 for the Fuel Teeth, the injectors will fire twice per engine cycle since they are batched, you would 24 only if the injectors are wired for sequential operation, since there are 24 crank teeth per engine cycle.

With 6 for the Spark Teeth, the coils will fire 4 time per engine cycle. If you use a value of 4, the coils will fire 6 times per engine cycle and the engine will run very poorly at best.

If you are not getting a good cam or crank trigger signals at low cranking speeds that are usually associated with low battery voltage you may want to adjust the Mag Pickup sensitivity in the AEMPro software. Use the values from my calibration as they work well on both my car and John's SC project engine. If that still doesn't remedy it, the pulldown resistors inside the EMS on the cam or crank inputs can be modified to increase sensor output.

 

[SuperRunner]

Sweet, thanks, I will give it a try.

Which values can be changed in the AEM. Only thing I see is RPM based sense, but nothing to actually change the gain.

 

[MitchP]

The RPM values change the sensitivity of the input from high to low. So if you have say 500 RPM for the Crank sensitivity values, it will be on high sensitivity (~0.5-0.8V to trigger) below that RPM and on low sensitivity (~2.5-3.0V to trigger) above that RPM.

You also may want to double check the wiring if the harness is modified and that your triggering edge is selected correctly for the polarity of how your crank sensor is wired.

If you can't get it to trigger reliably on high sensitivity, you either need to increase the pulldown resistor value on the ECU's adapter board or decrease the gap between the sensor and the trigger wheel on the channel you are having the problem with.

On the adapter board inside the ECU, the Crank input pulldown is a 2K2 in position R27, I'd try a 4K7 instead and the Cam input pulldown is a 2k2 in position R26, again, I'd try a 4K7. You'll need to run some type of pulldown resistor with a magnetic sensor so that the voltage output of the sensor is not excessively high (+50V) which can cause other issues. I still have the original 2K2 pulldowns on my EMS and have not had any low cranking speed cam/crank signal issues on my car.

Hope this helps.

 

[SuperRunner]

nothing has been modified on the harness except for the map sensor.

Then of course I am using 2JGE igniters. Bolt right up to the stock bracket.

Trying to make it as easy as possible for future people.

 

[MitchP]

The stock 1UZ igniters work fine too. Have you pulled the coil transistors off adapter board??? If not, the igniters may not be getting the right signal which can cause timing drift.

 

[SuperRunner]

if I use 2JZGE igniters, you don't have to do that. The 1100 and 1130 AEM was designed to run them.

 

[MitchP]

The 2JZGE igniters are probably the exact same thing (PN's???) internally as the 1UZ igniters. Do they plug right in???

They work because you probably don't have your secondary O2 sensors plugged in or the transistors in the ECU haven't acted up or broken down yet.

On the 1100/1101 EMS's, the coil outputs are on pins 52B through 57B, paired together internally so that the 2jzgte can be run wastedspark using only three coil outputs of the EMS. On the 2jzgte, all six of the pins are used and on the 2jzge only one of them are used, but on the early 1UZ's 4 of them are used. Two of them are for the coils and two are used for the heaters on the secondary O2 sensors, pins 52B & 53B.

With the secondary O2 sensors plugged in, there will be battery voltage (~12V-14V) at those two pins of EMS which are connected to the transistors (NPN) inside. Applying that voltage to that transistor terminal (Emitter) while sometimes having 0V at another transistor terminal (Base) exceeds the maximum rated voltage of the transistor and could lead to it's failure.

If either of those two transistors on pins 52B & 53B fail, it could effect the transistors they're paired up with, which are the ones that trigger the two igniters on a 1UZ. This could cause ignition misfires and/or possibly no ignition at all. I decided to remove mine so that there's no chance of that happening and possibly leave me stranded somewhere. At the very least, the transistors would be damaged and the ECU might not fire the coils correctly if it were put on a 2jzgte.

So, I recommend either leaving your secondary O2's disconnected or remove the transistors from the ECU.

 

[SuperRunner]

I didn't noticed the secondaries were plugged into the other igniters outputs, and that explains something. I did in fact fry my 1/6 igniter driver and had to use 3/4 instead. I figured I had fried it because I didn't have a good enough ground on the igniter, guess it was those darn O2 sensors.

 

[stevechumo]

Mitch gave me a ride in his tuned SC and it was so sweet. The power is very responsive and powerful. The auto tranny shifts so quick like a stick tranny. Imagine there's a forced induction system under that hood.