Honda B16A couldn't start with correct trigger offset

[Lokman]

Hello,

I have just built an B16A engine (Compression ratio 12:1)

The problem I current facing is I cannot start my engine with the correct trigger offset.

I have checked my trigger offset with timing light, which should be BTDC -78.

But with this offer in the ecu, the engine is always fail to start.

I have tried different method. By putting trigger offset to BTDC -30, the engine could easily start. But this is advanced like 48 from the correct angle.

After engine start with trigger offset BTDC -30, i can switch to BTDC -78 and it idlse smoothly.

 

I will be appreciate if anyone had similar problem like me, how could i fix it? Thanks

 

P.S.:

Attached a log, engine start with trigger BTDC -30 and idle at -78

Engine still using powercable for sparking

Is it possible High Crown piston causing this problem?

20240705.llgx

Engine could start with stock ECU easily.

I am appreciate for anyone helping.

Does it have function cranking engine with advanced offset?

[Adamw]

Can you attach your map.  Is it still using the stock coil and ignitor in the distributor?  

[Lokman]

Yes, it is stock distributor.

Attached my map.

 

TRUE IGNITION 20240705.pclx

[Lokman]

6 hours ago, Adamw said:

Can you attach your map.  Is it still using the stock coil and ignitor in the distributor?  

Yes, it is stock distributor.

Attached my map.

Thanks

[Harold C]

Hello Lokman,

I'm interesting about your thread. I'm also working on a B16a engine with stock distributor. (no crank trigger - only cam trigger)

I have below setting since 2 years now but no real issue for cranking (may be slow cranking, but not sure if it is linked).

Now I am just thinking again about redoing timing / sync / trigger.

I saw in your recording that you have trigger error :

 

@Adamw Hi !
Is it normal that Trigger Signal 1 is not steady (in the recording) ? (space between spikes is not very consistent even if engine rpm is more or less stable) (or may be it is related to recording frequency)

(I have same trigger irregularity displayed (without error) - at idle, pops at exhaust - want to know if that could explain it)

Thank you in advance for your support.
BR,

HC

[Adamw]

That is normal, trigger 1 state should say "counting" most of the time and should spike to "tooth after sync" for a very short period (1 tooth long) once per cycle.  The reason the spacing between the spikes is inconsistent in your log is because you are only logging at 40Hz, yet a single tooth would pass the sensor in about 5ms at idle so the log will only capture the spike when it happens to occur at just the same instant that the log sample is recorded.  If you do a trigger scope you will see every sync event.