kjewer1

iTrader: (4)

I want to verify that injector timing is correct on all cylinders, but to do this I need to know what actual cylinder Ign Tooth #1, 2, 6, and 7 correspond to. I could probably *** around with it and figure it out but my garage is an hour away, and I won't be out there for another week at least. If anyone has this information, I would appreciate it. I've searched the AEM forums until my eyes bleed and I get no actual answer.

To give an example of what I am looking at, Injector Tooth 1 through 4 seem like they could represent injector 1 through 4, they follow the firing order at least. Ignition Tooth 1, 2, 6, and 7 on the other hand do not follow the firing order, and when watching the offset between Ign X Firing Location and Injector X Open Location, only 1 and 2 of each line up. Ign Tooth 6 and 7 are off by 180 crank degrees or 1 tooth from Injector 3 and 4, in opposite directions.

Thanks in advance.

LetItBreath

I'm a little shaky on the whole tooth thing...is it actually the physical teeth on the sensor wheel?

kjewer1

iTrader: (4)

Pretty much. If my thinking/memory is correct, our crank sensor effectively has two teeth, and with 2 revolutions per cycle, that's 4. The cam sensor tells the ECU what tooth is TDC of the cyl 1 compression stroke, most likely. The problem is that the software doesn't tell you WTF tooth is what cylinder as far as ignition firing location is concerned. Odds are I'm never going to get an answer on this, and I'll have to drive an hour out to my garage to figure out myself. Hopefully I can find some time on thursday.

Spaceball 1

iTrader: (8)

There has to be much easier way to figure this out everyone has a different way and different numbers. There has to be a set map for this the only thing that would change the values would be cam choice and cam gears.

kjewer1

iTrader: (4)

There is much more involved in injector advance, depending on the strategy you choose, especially once IOTs become greater than intake valve open time.

Ackerson

Kevin

Is there any chance you'll make that spreadsheet available for other AEM users? Thanks

kjewer1

iTrader: (4)

I would, but until I can find that 3 mph I'm losing to my DSMlink ECU, I consider myself a ****up still... When I get it all sorted out I may make it available. The biggest problem is time and cost for the dyno time I need to really figure this out the way I want to. It's more cost effective for me to just have a proven EVO EMS tuner tune it and backwards figure out what they do, but I don't feel like traveling for that any time soon. And so it waits...

Ackerson

It looks like were in a similar situation. I'm getting to the point where I'm probably going to end up paying somebody to tune the car. It's about 80% of where it should be and I think experience and knowledge of the system is what's holding me back. I've read a lot about tuning the injector timing on a load holding dyno and that makes sense to me, but I don't have access to one, and if I did the time it takes for me to tune it wouldn't be cost effective.

RunThat

iTrader: (20)

bump for some answers

BBrooks

Ign tooth 1-10 are for each coil output just like you noticed with the injectors. The confusing part is the ems has 5coil driver outputs and 5 virtual(wastespark) outputs firing the same coil twice. Example Ign tooth 6 (coil 6) when turned on is tied to ign tooth 1(coil1) and ign tooth 7 (coil 7) is tied to ign tooth 2(coil 2) and so on. Also worth noting is one of the coil outputs is used for the MPI relay(coil5). Depending on the number of teeth on the crank sensor you use, you would designate which coil fires and where with the A tooth count read by the tooth control table. A tooth is the count of teeth on the crank sensor after the tooth control table filtering has taken place.

So as you said, 2 teeth counted twice per engine cycle. So 4 teeth, but in the tooth control table you'll notice coding of 6-1-6-1 etc. This is telling the tooth control table to process every other significant edge from the crank sensor. In the crank settings you'll notice both rising and falling edge are selected as a significant edge for the crank sensor. So the tooth control table is counting up to 8, but is only giving an A tooth count of 4.

The reasoning behind this i've read is less than an 8 tooth count the ems buffer can't sync low enough in rpm for the engine to start.

hope that helps

GTVEVO

iTrader: (22)

Aby@MIL.SPEC or Spaceball have either of you tried stopping your max injector advance timing right before the intake valve opens or at the beginning of cam duration? This was my latest test on this subject and it has me running a max of -25 deg ramping up from --180 at idle and hitting my max injector advance (-25) around max torque. I am running GSC S2 cams with a 107deg centerline on the intake side.

kjewer1

iTrader: (4)

99% of people can just copy what the factory does and it will run very well, no 3d advance required. The stock ECU's injector timing scheme is very simple and has changed in 20 years. RTFM for details, but essentially it injects very early to get atomization from the hot intake valve. The only change I made was to start to advance the start of injection when the end of injection would go past IVC. It's easy to build a spreadsheet to do this for you, and just copy/paste into the injector advance table, once you have injector phasing synched with a physical crank location. And you don't need to even think about how the teeth stuff works either, just know that there are two teeth per revolution and 4 per cycle. I've posted on the AEM forums and maybe here which injector tooth corresponds to which cylinder, and also for ignition. From these you can watch the paramenters and get the injector phase synched up with physical crank angles so you know what you are actually doing in the Advance table.

Spaceball 1

iTrader: (8)

GTVEVO and Kevin,

Sorry I let this issue go from when I first brought it up, but with the success GTVEVO had with the ign duty cycle and since winter has started I have the time. I have taken a look at my collection of maps and have found that basically most people including the big name shops are running the AEM given injector advance map. I still can not believe how nonlinear the map is, it can not be even remotely correct. I feel that it should be a somewhat linear graph with the exceptions of the resonance freq/flow characteristics of the intake manifold/turbo/cam used. I will start to also take a look into this. There has to be an easy way to make a correct map. The only thing that would have to be a “guess” is the time that the fuel charge would take to get from the injector to the intake valve at a given rpm/load. I know there could be a mathmatical equation for this also but i think we could just assume a small delay.

Kevin do you some how have the Factory Mitsu injector advance map or is it not just that easy to pull from the factory ecu?

Spaceball 1

iTrader: (8)

I just looked at the 9 map given from AEM and it is very different, very linear and also the injector phase is 3.50 instead of the 2.30 on the 8. The older mistu maps are also linear maps with different injector phases also.

Spaceball 1

iTrader: (8)

I just went out and did the procedure from the AEM forum and found my setup to be similar to the 9 calibration given from AEM...

The off idle rev is way better than before, but this is just feel and sound. I guess i could log rpms acceleration.