Ecumaster Classic trigger / ignition issue ? engine won't start...

Hi guys.

I'm not super familiar with ecumaster and I can't seem to be able to figure out why the car I'm working on won't start.

The engine is a 7MGTE bottom end with a 5MGE head, 300+° custom camshaft by catcam, high compression pistons and ITB.

The owner of the car decided to install only one trigger on the crankshaft (no cam sync).

The trigger wheel is 36-1 and the sensor is ~125° before the missing tooth.

On the ignition side, it's a Bosch double fire coil 3x2. (basically 3 wasted spark passive coil)

Ignition output is set as follow:

output 1 = cylinders 1 & 6

output 2 = cylinders 2 & 5

output 3 = cylinders 3 & 4

Engine firing order is the classic 1-5-3-6-2-4.

I checked the trigger signal on the scope by cranking the engine without any sparkplug and the fuel pump disabled.

I then connected the coil with only one spark plug on the cylinder 1 lead (spark plug touching the ground, but not on the engine) to check the timing.

After many attempts, the engine would not start. It almost feels like the timing is wrong on some cylinders ?!

I must have been missing something here...

PS: I sadly don't have any logs, my computer shut down on me before I could save anything.

PS2: the car is a few hours away from me.

Is RPM reporting correctly while cranking, the timing light test showed timing is on time, you aren't getting triggering errors?

Your issue may not be triggering related. Perhaps spark or fuel?

Yes RPM is reporting correctly and no trigger errors.

But the RPM trace on the graph jump up and down.

Since I don't have a log or a screenshot: it look somewhat like this: /|_/|_

/: Climbing to around 1100rpm, |: shot down to maybe around 200rpm, then flat at 3/400rpm.

Also when cranking, cylinder 3 & 4 where popping thru the ITB.

So after a bit of thinking, My best guest would be that maybe 2 outputs are inverted ?!

I didn't check the ignition outputs order (connection) myself, just took the informations provided by the owner as true...

here is a video provided by the owner:

Bonjour Ludovic!

Jumping RPM in a log could indicate wrong trigger settings, it should be sitting around 300rpm relatively stable. Are you sure you aren't running a 36-2 wheel? I'm not sure it would give an trigger error if you would be using 36-1 vs 36-2 trigger settings with the wrong wheel (I never tried it personally).

Next time you have access to the car, I suggest you do a Scope Log to confirm the trigger wheel configuration.

It's not just on the log, you can ear the engine doing it. When I set the trigger angle the RPM was rock solid.

And yes definitely a 36-1. it's a big death wheel on the crank pulley, you can't miss it.

Next time I have access to is Saturday. I try to have all possible causes by then so I don't loose another week.

I don't think the injectors phases could be the source ?

Since there is no cam signal I set them on the same order as the firing order and "squirt twice per cycle" is activated.

Another simple test would be to unplug coils, injectors, crank the engine and see if the RPM trace is stable.

The spikes you're seeing may be from combustion occurring in some cylinders, some of the time, rather than a triggering issue, so it helps to narrow that down.

If everything looks great without fuel, spark, then you're looking when the coils fire, when the injectors are pulsed, are they all in good working order, no spark plug issues, you have proper fuel pressure, coils are being charged the correct dwell time, injectors are being pulsed for the correct duration, etc.

Well, I found the issue !

It was a trigger error, or to be exact a conflict between the trigger and the ignition.

The trigger wheel was set as 6 teeth + 65°, in other words 125°. So the missing tooth was exactly on the "window" of the ignition for cylinders 3 & 4...

removed the trigger wheel, moved it so it was outside of the ignition of any cylinders, put it back on and the engine fired right away !

Now I have a bunch of other issues but they are mechanical. (Never buy ITBs from whitleytune, they are garbage...)

Good work!