1st Gen Haltech ECU Discussion

@treyus30

Finally got around to dialing my injector dead time a little bit last night. My particular injectors are the teal top, silver body 2jz 312cc injectors.

On my ECU, I have an Injector Deadtime Tuning tool that oscillates the injection mode between batch and sequential injection.



I turned closed loop O2 feedback off, and held the engine at a constant RPM and took a log. The first log is 1.2ms dead time @ 13.5v. The green square wave is the injection mode alternating between sequential and batch, mode 1 is sequential and mode 2 is batch. As you can see, there's a marked difference in AFR as injection mode flips.




Lowered dead times, 1.03ms @ 13.5v. AFRs getting closer together.



Lowered dead times again, 0.95ms @ 13.5v. AFRs are now pretty close between sequential and batch. So I know I'm on the right track.


The next step (which I haven't done yet) would be to introduce a new voltage and then rerunning the test. Easiest way would probably be to just disconnect the alternator to lower the voltage. Repeat the test, find the correct dead time at the lower voltage, and then draw a straight line between the points. Hope that makes sense.