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Discussion Starter #1
Hello,
I´m having trouble with my Alfa 156 JTD (2002) 88KW
While driving, my motor suddenly shuts down then the sound beep,beep,beep and display shows Motor control system failure then it disapears and shows engine oil presure low and I cannot start my car for couple minutes. After a while I can finally start it and it runs normally again. Sometimes it happens more than once for a ride but 99% of time it happend while driving down the hill. As far as I can remeber it didn´t happen on level road.
My local mechanic suggested it is something with ERG ventil so he closed it but it still happens. I have tried many things during this two years such as clearing whole fuel system, changing some sensors (unfortunately can´t remember which as it was long time ago) but the problem occurs every now and then. Sometimes it seems to be solved and then after half a years its back.
Enough is enough and I´ve decided to change mechanic but would be very helpful if anyone had similiar problems and would be able to share his thoughts/suggestions.
 

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Sounds like crank sensor.
When they fail they fail when hot and at that point the ECU thinks the engine isn't turning any more so cuts the fuel (and sparks on a Petrol).
Because rpm drops to zero there is no oil pressure, so on systems with a warning display and beeper you get a noticeable warning, but it is just an after-effect of the engine cutting-out.
 

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Sounds like crank sensor.
When they fail they fail when hot and at that point the ECU thinks the engine isn't turning any more so cuts the fuel (and sparks on a Petrol).
Because rpm drops to zero there is no oil pressure, so on systems with a warning display and beeper you get a noticeable warning, but it is just an after-effect of the engine cutting-out.
But the engine is still turning when it cuts out on the run?

Is the ECU still looking for oil pressure even when it thinks the crank shaft isn't turning?
 

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When the engine cuts most people will dip the clutch rather than judder to a stop with the engine braking them, so the engine will stop.......
 

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Discussion Starter #5
Sounds like crank sensor.
When they fail they fail when hot and at that point the ECU thinks the engine isn't turning any more so cuts the fuel (and sparks on a Petrol).
Because rpm drops to zero there is no oil pressure, so on systems with a warning display and beeper you get a noticeable warning, but it is just an after-effect of the engine cutting-out.
I´m definetely gonna suggest it to my mechanic as it seems logical to me and it´s not that expensive so I just might start with that. Anyway do you have any idea why it does happen 99% of times while driving down the hill?
 

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Discussion Starter #6
When the engine cuts most people will dip the clutch rather than judder to a stop with the engine braking them, so the engine will stop.......
Not sure, if I have understood you correctly but in my case you can dip anything you want but nothing will happen, after the MCSF alert car suddenly switch off that means power steering goes off as well and Its kinda scary when it happens in front of some twist or when there are cars behind you and you have to stop in places ,you normally wouldn´t.
 

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Not sure, if I have understood you correctly but in my case you can dip anything you want but nothing will happen, after the MCSF alert car suddenly switch off that means power steering goes off as well and Its kinda scary when it happens in front of some twist or when there are cars behind you and you have to stop in places ,you normally wouldn´t.
Yes, understand what you say. I was answering "the Editor's" comment that the engine would still be turning, driven by the transmission, which implied that the engine would maintain oil pressure. What I was suggesting was that if the engine cuts out, the natural reaction is to depress the clutch pedal to allow you to coast rather than have the non-running engine bring you to a halt in the middle of the road...the fact that you say you lose steering power assistance reinforces that.

With a crank sensor failure it normally occurs at relatively low engine speeds - I've managed to get home about 90 miles with a failing sensor on a TS by keeping the revs above about 2500 - needed a few instances of knocking the car out of gear in advance of junctions and a bit of clutch slipping, though.
 

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With a crank sensor failure it normally occurs at relatively low engine speeds - I've managed to get home about 90 miles with a failing sensor on a TS by keeping the revs above about 2500 - needed a few instances of knocking the car out of gear in advance of junctions and a bit of clutch slipping, though.
Yep, when mine first went it failed after driving from London to Snetterton, it cutout as I rolled to a halt in the race paddock and wouldn't restart.
Started and moved fine a hour later.
Then drove all the way home to London, including the usual traffic queue through Thetford Forrest and it cutout as I pulled up outside my house!!
 

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Discussion Starter #9
Yep, when mine first went it failed after driving from London to Snetterton, it cutout as I rolled to a halt in the race paddock and wouldn't restart.
Started and moved fine a hour later.
Then drove all the way home to London, including the usual traffic queue through Thetford Forrest and it cutout as I pulled up outside my house!!
This experiences all strenghten the idea of crank sensor being the reason in my case as the symptoms are similar. Thank you guys might as well start with that.
 
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