E85 starting problem

Hi,

we are building a cosworth YB engine with a Ecumaster sandalone.

We have some problem for start the engine, sometimes the engine is running very well and sometime the engine don't want to start. We wait couple of seconds and the engine start normaly

When he don't want to start you can crank minute but nothing, the spark plug are always dry but we see E85 on the pistons.

i m missing somethin but what ?

The compression ration is 8:1 on this engine.

if someone have ever see that...

thanks a lot

Does your ECU achieve sync on the first crank? Is there a prime pulse that runs each time the cranking starts? Perhaps that needs to be twice as long to start the first time.

Are you using regular relays or a PDM? If the former, can you check the voltage draw over the relay to check they are closing properly and/or don't have a deposit build up that might interfer with the operation? Ditto with them getting power and ground?

The other thing to check is the wiring - sometimes there is an intermittent problem that just shows every now and again, but when it clears it continues to make contact?

I just find my mistake yesterday evening.

The customer put Civic EP3 coil on the engine (without camshaft sensor) so for me the ignition must be 1-3-4-2 but 2 lap for the crankshaft for 1 lap for the camshaft.

So like that you have 50% of chance that you will spark at the wrong crankshaft lap that why the engine sometime run perfectly and sometime nothing because we sparl in the bad cylinder ( 1 instead of 4 for exemple)

The solution is to always spark in the same time 1-4 and 2-3 like that you always have a cylinder in compression realy to burn (1 or 4 and 2 or 3).