Hi everyone. Posting in case someone has had something similar happen…and if so pls feel free to respond or DM.
I have an EMU Black controlling my vvti 2jzgte. I have checked and double checked all my wiring and it looks good. I am running sequential ignition and can only get the car to start if i set my firing order to 1-2-3-1-2-3. I don’t understand why this is. I have a few more ideas im going to try this afternoon upon getting home from work but in the meantime am posting this.
As expected, once it starts it runs very poorly since only 3 cyls are firing. I then change to 1-5-3-6-2-4 and the engine smooths out. If i turn it off and re-start i will fire right back up. But upon cold/first starts it’s not doing the trick. I’m at a loss.
09/30/2026 -
Update 1: Checked continuity
coil 1 → Gray 8 coil 2 → Gray 16 coil 3 → Gray 9 coil 4 → Black 14 coil 5 → Black 1 coil 6 → Gray 1, all checks out.
Update 2: Checked timing
What you describe points to a cam sync problem during cranking rather than an ignition wiring fault.
Why this happens
- With the 1-2-3-1-2-3 firing order the ECU works only from the crank signal (wasted spark style), so it doesn’t need the cam signal. The engine always starts, but with individual coils only 3 cylinders fire.
- Full sequential (1-5-3-6-2-4) needs a valid cam signal to know which part of the 720° cycle the engine is in. If the ECU doesn’t detect the cam signal while cranking, it can’t sync and the engine won’t start.
- Hot restarts work but cold first starts don’t. That usually means the cam signal is marginal at cranking speed. A cold engine cranks slower (thicker oil, battery voltage drop), and a VR sensor produces a lower voltage at lower speed, so the signal can drop below the detection threshold.
What I’d like you to do
Please make a trigger scope capture during a cold crank (first start of the day, sequential firing order), together with a log of the same crank. Then post both here along with your project file. This will show straight away whether the cam signal is there, what its amplitude is, and whether the ECU gets sync.
artur
Hi Artur,
Thank you for responding, i attach wwhat you requested below. Admittedly even though I have years of wrenching i am not very familiar with cam sync and/or tuning in general. This was my childhood hotboi car and now in my 40s i have time to play with it and enjoying the process much more!
20261002_1027.emublog3 (63.5 KB)
2jzgtevvti.emub3 (65.6 KB)
scope_2026102_1026.emubscp3 (622 Bytes)
Update: i switched back to wasted spark, starts right up. Cam snsr has a bit of oil inside connector.