Engine cut out with no obvious signs of issue - ECU fault?

[Mikey p]

Hi, I was driving home from track day the other day and at constant throttle the engine cut out and coasted down.

It was not a power loss as as the rev counter driven from the Ecu remained active.

Pulling the data everything looks OK. Tps, rpm, reported fuel, spark adv, voltages fuel pressure etc..
It was almost like the fuel got switched off? Lambda goes lean.

It runs a s60pro running sequential and this is the first issue ever like this. Once I had coasted down I dipped the clutch and engine speed dropped to 0rpm before hitting the starter and off she went again..

To me it sounds like a possible ecu issue

Any one had similar? I presume it didn't loose sync as it still looked OK but I have added cam/crank errors to the logger.

Thanks.

[stevieturbo]

Is that the actual log file from when it cut out ? if so, upload it, screenshots suck. I don't see rpm drop to zero and a dead stop there ?

You think the fuel got shut off....so is the fuel pump still working ? does it have fuel pressure ?

The ecu is obviously alive and recording in that clip, it appears to have fuel pressure etc and rpm is showing.

If the apparent lean instance is where you say it died....then first things to check are spark, and power supply to the injectors.

[Mikey p]

It is where the incidence occured and the cursor is in the period where it lost drive and coasted down. I will upload the log file shortly.

Fuel supply had no issues according to the log. Fuel pressure is measured in the rail so should be reasonable.

It fired right back up after I lost drive and still working now..
Nothing has been found in terms of loose connections or loom damage. I agree that all was appearing to be working OK...

[Mikey p]

https://www.dropbox.com/s/8awohc13kbgqj ... l.Dat?dl=0

Log file in that link.

562.02 seconds is where it lost drive. Engine restarted 569.10 seconds.

Thanks

[stevieturbo]

Everything is pointing to either a loss of power to injectors, or a loss of ignition.

The ecu is alive, it still believes it is running ( because the crank is still turning ), it is trying to add fuel, it has fuel pressure.

Really doesn't leave many other options.

[Mikey p]

Agree. It didn't smell of fuel (I'm sat right next to exhaust) and started on the button as normal so expect it was fuel that dropped out rather than spark. I will continue to run it and see how it goes and if it logs any cam sensor faults. Spoke to Alex today and he was confident that it wasn't the ecu but said if it had lost sync it would have dropped engine speed and reported no injection so that doesn't leave me with much to check whoch i havent already.. I am sourcing a spare cam sensor just incase and have a s80 in the garage which I could swap over to to help locate the issue if it gets worse.

[stevieturbo]

It isn't reporting no injection though.

I guess one crude way of quickly seeing a power dropout is hook up a bulb to the 12v supply to injectors or coils tat you can see when driving.

Has it only done this once, or a few times ?

[Mikey p]

It's done it once. Have maybe done around 2 or 3 hrs of use since and its been OK.. if it does it more it will be easier to fault find but I'm pretty lost currently as to the cause.