Ted7

I'm with you there, if the engine was just turning off, but what I don't get is that it restarts immediately without hesitation as soon as I depress the clutch

Tach shows zero as soon as the engine cuts off and before I depress the clutch.

But can it be only the tach that is losing power and nothing else, like headlights and dashboard? You can clearly hear the engine cutting off the same way it would with the key.

Now you're just asking the same question as me. I can go through simple issues. Complicated ones, I'm out.

It doesn't contradict anything. I tried several times to explain this situation, maybe I should do a video. 1. Car runs fine, very well in fact, pulling hard, no misfire, nothing. 2. Suddenly engine stops (or die, or shuts off, I'm not sure how many different way I should be explaining this, needle is at 0 RPM) 3. Depressing the clutch restarts the engine which runs at 1,100 RPM, which its normal idling speed. This is normal since the clutch is depressed. If I let the car rolling with the engine off, it won't restart, only depressing the clutch will restart the engine. I can't try to restart with the key while car is in gear. Hope it's clearer, it is not something easy to describe and I'm not trolling the forum.

It's off, RPM needle is falling down to zero while lights are still on. I would hear it idling. Tried this, it doesn't work. Only depressing the clutch works.

I haven't but could try. What would it means?

You are. The engine is shutting off, as if I was turning off the engine with the key. It is completely dead and restarts at idling speed when I depress the clutch.

Will do when I get to the car

Clutch fully disengage. The transmission has been rebuilt too when the engine was out, and I had the issue before the full rebuilt. The car moves without effort freely when in neutral. Been on this for over a month now

That is correct. What's weird is that the car restarts without cranking or releasing the clutch. It can happen 5 times on a 10 mile drive or not at all on a 20 mile drive. Totally random, no matter how fast it goes.

Accelerating or cruising, never when I brake. When I push the clutch the engine restarts idling. All electronics, well there's not much electronics, but when it happen at night, lights and dashboard are still on. No electrical interruption. Nope, no safety switch I can try that when it's possible to pull over. I'll try to drive in a calm area That's exactly why I posted here Another solution is to put it on a dyno and try to reproduce the fault while plugged to a diagnostic system.

Original drivetrain since new back in 2005. It's a LHD and the car was doing that thing before the engine has been taken out for a rebuilt. It's only more frequent now :/

It's a 2005 with a 2003 Zetec SVT engine. I converted the headlights to the new style. I might be wrong but Zetec SVT were only produced in 2003-2004.

I push the clutch while it still rolling and it restarts. No starter involved. I don't go to a complete stop since I'm in gear. As soon as I press the clutch the engine restart on it's own, no turning the key, no starter noise, it just restarts. Believe me, in years and years of driving many type of different cars, I've never experienced this.

It restarts as I'm rolling as soon as I'm depressing the clutch. No need to release the clutch or turn the ignition key.

Professionals here don't want to touch this car. I went to a professional once who forgot to add oil and seized my engine.

Completely off but restart without cranking it when depressing the clutch.

Not the clutch, it has been changed with the transmission and it was doing this before the swap.

Stock ECU

Yup. Bypassed it for testing.

I'm suspecting that too. Investigating.

It's not equipped with an interlock switch. I can start the car normally without depressing the clutch.

It doesn't, the engine is restarting without turning the key or whatsoever, it just... comes back to life That's very weird...

It also happens under acceleration too. The only time it won't happen is if I'm at full stop.