What does AEM EMS injector phase do?

[tabio42]

FUEL>ADVANCED FUEL>INJECTOR PHASING>OPTIONS

The very top box is called injector phase. I know it is used to retard or advance the opening of the injector. And I've been told that a larger number is a more retarded state. What I wanna know is what does this reference and what exactly is it? It seems like the units are in crank signal teeth but I don't know how the value entered adjusts the injector timing.

Anyone?

[Blak94GSX]

A larger number means the injector starts to open closer to TDC, although determining where TDC is in relation to the injector firing is tricky at best.

For the most part, you want a linear scale from about -200 to +200 following the RPM. In general you adjust the phasing at each RPM point until the engine runs smoothest there.

[tabio42]

Thanks for the reply! Since I know you know everything there is to know about the EMS I'd like to pick your brain a tad bit.

I'm thinking you're talking about the 3D Engine Speed, Engine Load, Injector Phasing Map. I was trying to figure out Options-Injector Phasing - where the injector tooth inject options are set (Injector 1 at tooth #0 etc.) and the first option above the injectors is Injector phase. The value in the base calibration is 2.3 . I don't know what this 2.3 represents. What I was trying to do was globally retard my injector timing to try to get rid of a lean spot on spool-up which I am thinking is caused by valve wetting from the injectors opening too soon in relation to the cam timing.

Whatcha think?

[Blak94GSX]

Definitely don't mess with that. It changes more than the injector firing order timing.

The lean spot is normal.

Also, make sure you aren't using Load Accel. The Trigger level should be set to 100.


If you want to globally change the injector timing, move the whole 3D injector phasing table UP more.

[tabio42]

Oops. I should have axed you before AEM. They told me that is the first thing to change when trying to advance/retard injector timing :-/

Well for experiment's sake I actually did two back to back runs - one with that value at 2.3 and one with it at 2.0
At 2.0 the lean spot went away but my entire air/fuel ratio got .2 points leaner. Also, previously the lean spot was followed by a slightly rich spot about 200-300 rpms after full boost. That went away on the run with the setting at 2.0 as well. And the last thing I noticed about that run was that the throttle accel had a much bigger effect at initial full throttle than it prevously had.

So I still don't know what that 2.3 number represents but I'll put it back to normal. Should I just increase the numbers in the injector phasing table by 6 since my cams are 3 degrees retarded?. Also you said that those numbers should peak at +200? The base calibration has them stopping at 0 at 4500rpm. Could that be part of what is causing the problem since I get full boost at 4250?

btw the more I mess with my computer the more I understand why you start from scratch when you tune people's cars.

[Blak94GSX]

Let me start over.

It sounds like you are starting with an AEM startup calibration. This means you will have to learn a LOT really quickly just to make the car run properly, since these files are anything but properly configured, although probably a safe starting point compared to the base cals posted on EVOm.

Step 1, go to Options, Full List. Look for anything that says Tooth on it (not teeth), and make sure it is set to an integer, like 1.0, 2.0, etc. Mostly these are going to be the Ign Tooth #01-#10, and the Inject Tooth #01-#10. On an EVO, the tooth setup goes 2, 1, 7, 6 for the firing order on the ignition, and 1, 3, 4, 2 for the Injector order. The rest of the Inject Tooth items, and Ign Tooth items should be 0.00. Then make sure the Injectors 1-4 are ON, and Coils 1,2,6,7 are ON. The rest should be OFF.

As far as sensor calibration goes:

-Set the TPS min/max voltage so the TPS is more than 0 and less than 1

-Make sure the Ignition Sync is 0.00 in Full List

-If you are using a wideband that is shown in the wizard, set the gain according to the instructions in the wizard, with the sensor unplugged from the harness

-If you are using a Zeitronix, set the gain to 1.00 and then set up the calibration table from the Zeitronix supplied table

-Run the sensor setup wizards for AIT, MAP sensor, Coolant Temp, Cam/crank sensor, and both of the Rev Limiter wizards with the Master Rev Limiter set to full hard, and the 2 Step set to full soft

-Run the wizard for the coil dwell setup

-Set Injector Phase to 2.00

-Inj Min 0

-Inj Duty Max 0.00 (limiter disabled)

[tabio42]

I love you for replying to me at 1:20 AM. I'm gonna check all that stuff tomorrow. I know that it lists injector #1 tooth to tooth 0. The tech guys said that the computer reads this as the first tooth. Is that wrong? And should I scale the Injector phasing all the way up the RPMs? I'm going to sleep now. I'll bring you treats when I bring you my car to tune.

[Blak94GSX]

(All parameters listed are found in Options/Full List)

Try starting the motor at this point. May require some creative use of the throttle to keep it running for now.

-Adjust the MicroSec/bit value until the AFR on the wideband is in range (12-14) so the engine runs sorta decent at idle

-Time to sync the EMS with the crank sensor
Use a timing light, preferably a really simple one with no knob on the back, or carefully zero out the knob if it has one. Go to Configure/ECU Setup, Set Ignition. Put 5 in the Fixed Timing box, set the radio button at the top to Fine, check the box for Ignition Fixed so it is checked On. Then with the motor running at around 2000 RPM, adjust the ignition sync offset using the buttons at the top until the timing mark is lined up real close to the first line on the timing belt cover (5 degree mark). The marks are T for TDC, then 5, 10. What you actually sync at for the fixed ignition value doesn't matter, just use whatever mark you can see best (I usually use 5, but 0 or 10 are also fine choices). The ignition is now synced at idle. Now rev the motor to like 6000 rpm steady and check the timing again (Ignition Fixed is still checked ON). See which way the timing moves as you rev it up. The timing drift is set by the value Pickup Delay Comp. A larger number here makes the timing go more advanced with the revs, and a smaller number gives less advance. Adjust this until the timing at the crank shown with the timing light is the same at 2000 and 6000. ONLY adjust the Ignition Sync value at low RPM, and then use Pickup Delay Comp to make sure the timing stays the same at high RPM. Do this step right and you are ahead of 99% of the "tuners" out there.

Basic steps from there in order:

-Idle% vs Target table
-Crank Injector Time table
-Fuel Map
-Ignition Map
-Throttle Inj Corr for part throttle
-O2 Sensor Feedback

A few dozen other things after that for fine tuning...

[Blak94GSX]

I love you for replying to me at 1:20 AM. I'm gonna check all that stuff tomorrow. I know that it lists injector #1 tooth to tooth 0. The tech guys said that the computer reads this as the first tooth. Is that wrong? And should I scale the Injector phasing all the way up the RPMs? I'm going to sleep now. I'll bring you treats when I bring you my car to tune.


0 is the first item in tooth land. So yeah that's correct, the injector for cylinder 1 should be 0.00 and the coilpack for cylinder 1 should be 0.00

It is a 4 cylinder so the first injector will be 0, then 1, 2, 3. Same for the Ign. It is important to note though that they may not go in order due to the pinout configuration on the harness, and the firing order of the engine.

[Blak94GSX]

On the original topic, the Injector phase table has a range of -360 to +357 and 0 is NOT TDC. The actual value to make the injector fire at TDC is relative to the Injector Phase value and the teeth range, plus some other factors. Basically you have to tune it, not calc it, but yeah just move the values up and down in large increments until it runs the smoothest at that RPM and Load.


Yeah I know it's screwy, don't blame me, I don't make the stuff :p

[tabio42]

Wow you made an awesome writeup :)
I'm not exactly starting from scratch. My car actually runs and drives pretty well (not as well as if someone like you had tuned it obviously). I did all the initial setups you mentioned except I was totally lazy and only sync'd the timing at low RPM. But now if I sync timing at 6000RPM I'll have to change the timing throughout the map I guess. And I never ran the coil dwell setup. I probably should have because my XS Ignition AmplifiX0R kept blowing my ignition fuse. I ended up lowering the coil dwell factor to stop it.

I've got my fuel and spark down well enough that it scoots nicely. But since boost comp is foreign to me I had to go through and do each individual load cell.

You said "-Set Injector Phase to 2.0" - that seems to solve the issue with the lean spot (followed by a rich spot) on spool. I don't know what the units are for 2.0 or what that number actually represents but since it works I'll leave it there. It does make the AFR's leaner overall but maybe that is because it is burning more of the fuel instead of it blowing through?

And since the injector phasing table is really complicated I'm not gonna screw with it. I don't want to find the spark event for each RPM range and do a bunch of adding and subtracting. That would give me a headace :)

This is all a learning experience for me. It is fun and frustrating at the same time. I really appreciate your help.

[Blak94GSX]

Injector Phase is a multiplier used in conjunction with the Injector Phasing table and Injector Battery Voltage comp table values. Altogether it is used to determine when the injector ON time begins relative to the crank/cam teeth. Basically 2.0 works good usually for the primary injectors, and 1.8 for the secondary injectors when using a dual fuel rail setup.

[tabio42]

Sweet, thank you. Advice taken and applied. One more question :)

Do you know a good way to clone an injector so I can give the aquamist a pulsewidth signal for it to duplicate?
http://www.aquamist.co.uk/cp/806-009/806-009.html
They want you to put a vampire clamp on your injector #1 output from the ECU and send that as a signal to the FIA box. I am not a fan of splitting current. So I tried to turn on injector #10 and give it tooth #0 so it fires at the same time as injector #1 but it made the car run lean.

[Blak94GSX]

Use the PWM User#1 output and use the MAP sensor as the analog input to scale the PWM for boost. The User#1 is normally used for the fan controller, but the fan controller can be rewired as on/off using one of the LS outputs.

[tabio42]

So the injector phase is at 2.0 now and it runs much better than the startup cal's 2.3. The lean spot as I hit full boost is gone. Since the stock injector advance map only advances until 3500 and plateaus, I tried to make it linear like you suggested. I made it go from -180 at 0rpm to +180 at 8000rpm. I did back to back runs to compare before and after. With the advance map scaled linear up to 8000rpm, it runs richer around 4500-5000rpm and gets quite a bit leaner at 6000-6500rpm (as compared to without the linear scale). Is this because more fuel is making it into the combustion chamber in the first part and less fuel is getting in at higher RPM?

The reason I'm messing with all of this now is because my car chucks out a lot of black smoke under WOT. I figured the fuel delivery was off and that was what was causing it.

[Blak94GSX]

Sounds like you just need to tune the fuel map now.

[tabio42]

So it's ok for the injector advance map to make a part of the fuel map leaner? The only thing AEM tells you is that you want the mixture to get richer because that tells you that more fuel is getting into the combustion chamber.

What I need is for my buddy to get that reverse osmosis water purification system frame off of his rack so he can weld me on a cat, a resonator and a plate on my intake pipe for the water nozzle. Then all of the variables are set and I don't have to worry about tuning it myself ;)

[Blak94GSX]

The fuel map and timing map must be near perfect first before playing with any of the trim adjustments. If the basic tables aren't done, the esoteric stuff will have unpredictable results.

[DTunedEvoX]

Reading this is like $300.00 of free stuff!

[tabio42]

The fuel map and timing map must be near perfect first before playing with any of the trim adjustments. If the basic tables aren't done, the esoteric stuff will have unpredictable results.


They were pretty good (11.2 all the way at full boost and no knock) but definitely not perfect. I experimented more and I'm pretty sure I've found a trend. The base cal's injector advance table stops advancing at 3500rpm. More injector advance from 4500-5200 makes it more rich, and more injector advance above those RPMs makes it more lean. I isolated the RPMs with injector advance and I confirmed it. I also saw that if you abruptly stop advancing the injectors or go from advance to retard, it creates a lean spike.

Therefore my analysis is that I am definitely not doing it right.