AEM EMS - First Impressions
#1
AEM EMS - First Impressions
Well after blowing my 1.6, I switched to a 97 1.8 motor. Today I finally got to the point of being able to try and start the motor. I purchased a new AEM EMS standalone, and decided to immediately delete my AFM. I jumpered the fuel pump leads to have the pump run, and completely removed the AFM from my system. Installed the AEM 3.5 bar MAP sensor, and AEM intake air temp sensor. I connected the 5 wires to my ecu harness, plugged it all in, and them plugged my laptop into the EMS. Opened the file labeled 90-93 miata, and then went into sensors. Chose AEM 3.5 Bar map sensor, and AEM intake air temp. Saved the file, and then turned on the car. The car started on second crank and idled. I was running open header so I only ran the car for about 10 seconds, but man, I'm impressed. Can't wait to get it on the dyno this tuesday and dial it in.
#3
I'm using it on a daily basis right now. There's a few little things that you need to do to get it to run properly on a MAP sensor. You have to go in to the sensors section, and under MAP settings, you have to tell it where you plugged the MAP into the ECU. I also went in and told the EMS that my MAF had no input at all. The base file was extremely rich, so make sure you tune it. A wide band sensor would be nice to have, because if you have one, you can just tell the EMS that you want X Air / Fuel ratio, and it will adjust itself on the fly to try and keep that AFR. It's really an awesome setup.
#4
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I'm using it on a daily basis right now. There's a few little things that you need to do to get it to run properly on a MAP sensor. You have to go in to the sensors section, and under MAP settings, you have to tell it where you plugged the MAP into the ECU. I also went in and told the EMS that my MAF had no input at all. The base file was extremely rich, so make sure you tune it. A wide band sensor would be nice to have, because if you have one, you can just tell the EMS that you want X Air / Fuel ratio, and it will adjust itself on the fly to try and keep that AFR. It's really an awesome setup.
I've been running one for quite some time and I can only report 2 issues that I haven't been able to solve:
1) Cranking the car to start it up takes too long. No one has been able to tell me how to fix that.
2) I have problems with the IAC valve compensation when I turn the A/C on. I just bought a used IAC valve to see if that's the problem.
BTW, I have a 96. If you need my settings or anything, just send me a pm.
#5
I've been running one for quite some time and I can only report 2 issues that I haven't been able to solve:
1) Cranking the car to start it up takes too long. No one has been able to tell me how to fix that.
2) I have problems with the IAC valve compensation when I turn the A/C on. I just bought a used IAC valve to see if that's the problem.
BTW, I have a 96. If you need my settings or anything, just send me a pm.
1) Cranking the car to start it up takes too long. No one has been able to tell me how to fix that.
2) I have problems with the IAC valve compensation when I turn the A/C on. I just bought a used IAC valve to see if that's the problem.
BTW, I have a 96. If you need my settings or anything, just send me a pm.
#7
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Guys; not many people I know have more AEM knowledge than Jason
Jason, my car is in the shop. We're about to start rebuilding the engine. As soon as I get it back I'll report about your question.
BTW, many thanks!
#12
2. AEM EMS has to match the timing pattern of the crank/cam sync signals to the pattern described in the calibration and only then it starts the ignition/fuel injection. Watch the "Stat Sync'd" parameter. Once it goes "ON" (EMS synced the crank/cam sync sensor signals) the engine should start almost immediately after that - mine does. If it doesn't you still have to tune the engine start options.
3. I remember an AEM engineer once posted about the "Sync Early" option helping the syncing happen faster which speeds up injection/ignition start too, but he also mentioned that it won't work with the Miata pattern. I suspect the reason is either that the Tooth Control Table in the Miata calibration has values for ignoring some edges (which makes detecting the pattern harder - it has to figure out the phase of which crank edges to ignore in order to match the signal), or that it uses alternative crank fire method (Crank Alt Fire = checked) to start the engine (Jason C found that the tooth timer is overflowing at large periods (Miata has just few crank teeth and periods get too big at low rpm) and to overcome this looks like AEM are using an alternative firing method (on significant edge) at low rpm. I guess I'll figure that part out once I finish making the OEM crank trigger into a 12 tooth one some day ...
#13
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1. If you have set fuel priming time, never ever try cranking the engine before the fuel pump has finished the priming. The ECU won't even try syncing the cam/crank sensors before the priming has finished. I just wait for the second relay click before I engage the starter. It syncs and starts quick after that.
2. AEM EMS has to match the timing pattern of the crank/cam sync signals to the pattern described in the calibration and only then it starts the ignition/fuel injection. Watch the "Stat Sync'd" parameter. Once it goes "ON" (EMS synced the crank/cam sync sensor signals) the engine should start almost immediately after that - mine does. If it doesn't you still have to tune the engine start options.
3. I remember an AEM engineer once posted about the "Sync Early" option helping the syncing happen faster which speeds up injection/ignition start too, but he also mentioned that it won't work with the Miata pattern. I suspect the reason is either that the Tooth Control Table in the Miata calibration has values for ignoring some edges (which makes detecting the pattern harder - it has to figure out the phase of which crank edges to ignore in order to match the signal), or that it uses alternative crank fire method (Crank Alt Fire = checked) to start the engine (Jason C found that the tooth timer is overflowing at large periods (Miata has just few crank teeth and periods get too big at low rpm) and to overcome this looks like AEM are using an alternative firing method (on significant edge) at low rpm. I guess I'll figure that part out once I finish making the OEM crank trigger into a 12 tooth one some day ...
2. AEM EMS has to match the timing pattern of the crank/cam sync signals to the pattern described in the calibration and only then it starts the ignition/fuel injection. Watch the "Stat Sync'd" parameter. Once it goes "ON" (EMS synced the crank/cam sync sensor signals) the engine should start almost immediately after that - mine does. If it doesn't you still have to tune the engine start options.
3. I remember an AEM engineer once posted about the "Sync Early" option helping the syncing happen faster which speeds up injection/ignition start too, but he also mentioned that it won't work with the Miata pattern. I suspect the reason is either that the Tooth Control Table in the Miata calibration has values for ignoring some edges (which makes detecting the pattern harder - it has to figure out the phase of which crank edges to ignore in order to match the signal), or that it uses alternative crank fire method (Crank Alt Fire = checked) to start the engine (Jason C found that the tooth timer is overflowing at large periods (Miata has just few crank teeth and periods get too big at low rpm) and to overcome this looks like AEM are using an alternative firing method (on significant edge) at low rpm. I guess I'll figure that part out once I finish making the OEM crank trigger into a 12 tooth one some day ...
I'm pretty sure there will come a day when they make sense. I can see many months of additional reading in my future
#15
So I've been monitoring my start up, and the car on average takes about 5 cranks before it gets synced. Once it's synced, it's normally 2 cranks to start (from dead cold). If the car is hot, and turned off then turned on a minute later, it starts in about 4 cranks. And if I leave the car for 30 mins to an hour, the car cranks for a very long time, and it says it's syncd. Any idea what settings I should be playing with?
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