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AEM Infinity Injector problem

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Hello everyone, I’m fighting with a 2JZ engine that my client brought to me. In the beginning the engine didn’t start, I found that the crank sensor was bad, now the injectors 4, 5 and 6 aren’t pulsing. The ecu is a AEM Infinity 506 with a custom harness. I got the engine running but only 3 cylinders are firing. There are no signal coming from the ecu to the injectors 4,5 and 6 when engine is running. I put the ecu in diagnostic mode and tested the outputs. During the test the ecu sent pulse to injectors. I tested all the grounds and positives feeds and everything is good.

The injectors are DW 1000cc high impedance.

The crank and cam sensor are hall sensor.

The trigger wheel has 12 teeth and the cam gear use one magnet.

I tried different injectors configurations, sequential, semi-sequential and simultaneous and none worked. We sent the ecu to get fixed because I thought the injectors drive was the problem, but the guy didn’t find not wrong with it.

Am I missing something? Can anybody help me? Thank you all!


My apologies if you've already performed any of these tests:

Verify 12V at all injectors at key on

All injectors are enabled in software, cylinder count is 6?

Have you checked triggering settings against known good values for that engine/ECU combo?

If you get stuck and want to test the ECU yourself in case there's an injector driver issue you could temporarily repin the ECU harness.

Have you confirmed there's no pulse from the ECU with an oscilloscope? I have found the AEM's diagnostic firmware behaves differently sometimes then the actual firmware. It does sort of sound like its in batch fire, maybe post a calibration file and we can take a look. Could just be a checkbox buried in a menu that you're missing or a trigger setting issue.

I'll also add that AEM's warranty department has sent back bad ecu's that they claimed were fine and after a bunch of arguing, retested and actually fixed so don't rule that out just yet.

Tyson is not alone in that experience. Performing your own testing of the outputs will give you more control over the diagnosis and outcome.

Thank you, Tyson and Mike, for replying to me. I checked everything again and the problem still. I'll attach the calibration file for you guys take a look and see if I forgot something. I'm just trying start the engine, so the configurations is very basic. Just for to give you guys another idea, the ecu and harness was installed in another Supra and the car owner bought it to his car, and he told me the other Supra was running fine when they took it out. I'll also attach the file that came with the ecu. The file Pump Gas 4 is the file thar I created. Thanks a lot.

Attached Files

Solved! For any reason the firing order was inverted. I swapped the coils pins outputs on the harness and it worked. Now the cylinder number one is in the back of the motor. I think it's something related to cam gear trigger. Thank you guys!

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