Engine cutting out
 

Hi,
I am running a 2004 CDTI which has and is running smoothly. This morning as I slowed down to come off the motorway, the engine cut out. It immediately restarted. For the final 4 miles it did the same virtually every time I slowed down. Each time it restarted with no problem. The check engine light has also come on.

Coincidental with this, last night the engine seemed to run normally just a touch after it was switched off. This morning it is doing the same, I switch off, remove the key and the engine still runs for about a second. Any ideas?

The HP fuel pressure regulator may be failing - it sits on the back of the HP fuel pump.

Worth getting the fault codes read before spending any money on parts though.

Thanks. I am hoping it's ok until I'm off on Tuesday. Unfortunately I leave in the dark and get home in the dark. I shall read the codes and bear your suggestion in mind.

Mike is spot on, this is almost certainly a HP regulator problem ;)
I have seen this type of fault when the radial wiring supplying the 12v rail to the regulator, MAF, rail sensor, glowplug relay etc etc has an intermittent connection ;)

Brian :D

Thanks Brian.
Is that the connector on the left under the manifold? Also, is that the approx location of the regulator?

Thanks

Hi Steve, it is hidden in the plastic trunking under the inlet manifold at the front of the engine ;)

The supply is fed from engine compartment fusebox fuse 1 and the diagrams I've attached for you :)

Brian :D

Thanks for that, it gives me a good starting place.

Hello,
I've just used a super cheap BMW compliant reader and the fault code P1090, "Pre catalyst fuel trim system too lean bank 1" comes up. Does this make sense,is it relevant and if so does it help confirm the initial diagnosis? The code showed 30 mins after I struggled home and had disappeared when I rechecked after another 30 mins. It reappeared as soon as the engine was started. The car drove ok for the first 5 minutes or so and then started cutting out when the throttle was eased off. By slipping into neutral (auto box) before coming off the gas the engine kept running. Made for an interesting 40 minute drive home.

Hi Brian/Steve.
These photo's below may help with the area of the wiring junction and the locations of the HPFP regulator etc ;) Arctic

Hi Steve
In my code breaker book it reads as below.

The voltage, frequency or value of control in the regulator circuit is incorrect (under fault ) Signal could be out of normal operating range, constant value, non-existent, corrupt, Possible fault regulator or wiring.

Eg regulator power supply short/open circuit, high circuit resistance or incorrect regulator resistance.

Note the control unit could be providing the correct signal but it is being affected by the circuit fault.

So pretty much what Brian as said already :D