What electrical circuit would stop a common rail diesel dead

[Pupp]

Have a 2.2 Laguna hack (I know) that has developed an intermittent glitch whereby the engine will momentarily die whilst bowling along (really good fun when in the outside lane of the A14 with an 18 wheeler up yer chuff).

I'm assuming it's an electrical issue as usually get some random warning lights including ABS and/or airbags plus the service light but not always, and the thing will then generally go weeks with no repeat.

As it's a diesel, I'm also assuming (maybe wrongly) that it's likely to be fuel system related but I gather the pump is mechanically driven so presumably that can't just drop out, and my knowledge of weasel workings doesn'y extend to knowing what else there might be that could/would cause immediate lack of go on failing...

Ideas/suggestions welcome

[Pumaracing]

The pump is mechanical like any old diesel but the injectors are electronic and controlled by the ecu. A fault in the wiring or sensors reporting to that could be the issue such as the crank position sensor, throttle position sensor etc. If it's so intermittent I'd just have general check round all the wiring plugs first. There might be a loose contact.

[Pupp]

Thanks, that makes sense and gives me half a chance

[Simon says]

Pupp,this kind of fault tends to plague Renaults of differing engine sizes and models and can be a right pain in the arse to rectify,don't want to scare but of 2 I know of that give these syptoms a new ECU was the answer and apparently speaking to an ECU doctor the build quality on said ECU,s is questionable sorry not much use really but one thing that does spring to mind is the crank angle sensor plug can play up on Renaults and give random cut outs from one week to the next try pulling the 2 pin multi plug on and off a couple of times (remakes the contact) check for water ingress or corrosion at the ECU & sensor connector/s you may get lucky,it seems unlikely but I have known the crank sensor plug to give cut outs/non starts at the most random time intervals

Edited by Simon says on Saturday 29th October 18:08

[Pupp]

Thanks for that info... again it makes sense as Ive had a code reader on it that does show a code equating to crank sensor after it happen. Thing is the sensor has been changed as has the plug but still occurring. Cetainly agree its a PIA!