[PedroV9]

Would anyone be able to tell me, based on these images, the correct Primary Base Teeth and Trigger Angle configuration?

Using a timing light, I found a value of -3 degrees, but I’m experiencing Lost Sync at intermediate RPMs. Checking with an oscilloscope, the signal looks clean, and there is also no reading fluctuation in TunerStudio.

I believe it might be an issue with the decoder settings.

[PSIG]

Please post:

• ECM version and any module versions attached
• Tune file
• Run log from pre-start, through normal operation, to breakup
• Tooth log
• Composite log

Let's see what the ECM is seeing, and the settings it has now. When taking a run log, be smooth and deliberate in operation, as excessive throttle play (except as required to initiate issues) clutters the info. Thanks!

[PedroV9]

I hope the files are correct. My Speeduino is based on a 0.4.3c, running the latest firmware.

[PSIG]

Are you using any VR or signal conditioner? My first guess is noise. You have 164 sync losses in 23 seconds. My next clue is your run log, which shows rpm spikes when the engine is off and not cranking. Finally, one of your composite logs randomly shows extra teeth that do not exist.

Two full crank revolutions with ghost teeth. The cycle (cam) signal is a bit weird also:

PedroV9 too many teeth.jpg (62.17 KiB) Viewed 937 times

As first steps, I would set the Re-sync every cycle to ON. Test. If no joy, test increasing Trigger Filter to Weak. Test. Try Medium if necessary. If results are not good, I would begin sweeping for electromagnetic noise (EMI/EMR) with an oscilloscope or even try an AM radio. If you sense some noise, try to associate the noise frequency with something operating electrically (alternator, blower, ignition, fuel pump, etc). If you are lucky, it may just be a bad ground. Others may have more ideas from your data. Good luck!

[LPG2CV]

Dwell looks a little high. Try setting it to 4.5 for cranking, and say 3 for running.

It may not fix it, but may save your coil from overheating.

Regarding Injector Opening Time. The use Whole pulse width is a legacy setting for older tunes. For a new tune you would normally use Open Time only. This has nothing to do with the sync loss issue though. You will probably need to retune if you change this.

[PedroV9]

Are you using any VR or signal conditioner? My first guess is noise. You have 164 sync losses in 23 seconds. My next clue is your run log, which shows rpm spikes when the engine is off and not cranking. Finally, one of your composite logs randomly shows extra teeth that do not exist.

Two full crank revolutions with ghost teeth. The cycle (cam) signal is a bit weird also:
PedroV9 too many teeth.jpg


As first steps, I would set the Re-sync every cycle to ON. Test. If no joy, test increasing Trigger Filter to Weak. Test. Try Medium if necessary. If results are not good, I would begin sweeping for electromagnetic noise (EMI/EMR) with an oscilloscope or even try an AM radio. If you sense some noise, try to associate the noise frequency with something operating electrically (alternator, blower, ignition, fuel pump, etc). If you are lucky, it may just be a bad ground. Others may have more ideas from your data. Good luck!

I'm using the original Hall sensor from the car. I made a plug-and-play ECU using an old OEM ECU case.

However, I found two issues:

The original alternator wiring runs inside the same harness as the crank sensor wiring.
The cam sensor wiring is badly damaged and exposed.
I'll check and fix these issues first.

The curious part is that the failure only occurs within a specific RPM range, between 1800 RPM and 2300 RPM.

Outside this range, there is no Sync Loss at all...

But it could also be due to engine vibrations causing the wires to touch each other intermittently or something similar.

Dwell looks a little high. Try setting it to 4.5 for cranking, and say 3 for running.

It may not fix it, but may save your coil from overheating.

Regarding Injector Opening Time. The use Whole pulse width is a legacy setting for older tunes. For a new tune you would normally use Open Time only. This has nothing to do with the sync loss issue though. You will probably need to retune if you change this.

I'm using the dwell time suggested by others with this engine running Megasquirt, but I will try reducing it to see if it improves.

About the injector configuration, can you show me exactly where to set it?
This is the first engine I'm tuning, lol.

[PSIG]

The original alternator wiring runs inside the same harness as the crank sensor wiring.
The cam sensor wiring is badly damaged and exposed.
I'll check and fix these issues first.

Good idea - fix what you already know is questionable or 'not right', and see where you are by then.