Mysterious starting problems - can anyone help?

[VersoVoyagers]

Hi everyone!

I have a Corolla Verso 2008 model, Diesel with 2.2 Turbo engine. It's been such a reliable car, but recently we've been having starting issues.

The starting issue sounds a bit like this video: 

This all started when we had a warning light come on for the alternator. Replaced that, got it home, and then, a few days later, these problems started. 

Back to the mechanic, changed the starter motor (which had become seized), and then the relay to the starter motor. Still the issue persisted.

Mechanic is really experienced and was utterly stumped. 

Any thoughts? As this man on the video mentions ECU, I thought I'd mention here that I've seen some people suggest upgrading it to software version 6, but that sounds all rather mysterious to me. Other suggestions have been suction control valve.

Loath to spend much more on this without something concrete at the moment; it's cost me over £1000 so far.

I'll take any advice that anyone has! Thanks in advance!

[HSJ]

I have the same problem on same model. Under 15 deg c it fails to started, I have to preheat the engine 3 or 4 times. I replaced the glow plugs, but it didn’t improve, but a mechanics told me that the Bosch glow plugs are not the best. I still think it’s the glow plugs, that's why you have to preheat 3 to 5 times. The ECU ? It doesn’t make sense, it’s a computer, who would it change ? It’s not the injectors either,  I had mine tested by Toyota, they were good.

Glow plugs : NGI recommended to me but I haven’t tested it. Toyota uses Denso glow plugs

[flash22]

If the plugs are timing out, it's an issue with the relay/controller

when was the fuel filter last drained/changed ?