How's this for coincidence??

[OzC36]

Alex,

I have a somewhat similar problem where the engine sometimes dies when idle throttle is selected either at a standstill or when decelerating at speed. The engine will run at above idle but dies immediately idle throttle is selected. After switching off and restarting, the engine bursts into life and either dies immediately or runs normally for an unspecified amount of time.

I changed the fuel pump relay (in the boot!) and the problem remained. I changed the MAF and the problem remained. After reseating all the fuses, the MAF and all relays that I could lay hands on, the problem seems to have gone away for the time being. But I know it is in hibernation awaiting a most inconvenient moment to respring its trap. I am going to change the overvoltage protection relay next.

Did the fuel filter change fix your problem?

 

[Alex Argent]

Alex,

I have a somewhat similar problem where the engine sometimes dies when idle throttle is selected either at a standstill or when decelerating at speed. The engine will run at above idle but dies immediately idle throttle is selected. After switching off and restarting, the engine bursts into life and either dies immediately or runs normally for an unspecified amount of time.

I changed the fuel pump relay (in the boot!) and the problem remained. I changed the MAF and the problem remained. After reseating all the fuses, the MAF and all relays that I could lay hands on, the problem seems to have gone away for the time being. But I know it is in hibernation awaiting a most inconvenient moment to respring its trap. I am going to change the overvoltage protection relay next.

Did the fuel filter change fix your problem?

OzC36

Regrettably, no it didn't! - Ironically everything seemed okay for a couple of days after the fuel filter change, and I also covered quite a bit of mileage. Fortunately, when the problem did occur this time, I was about a mile or so from home.

As previously anticipated, I ended up taking it into MB Bury St Edmunds last Thursday for a star diagnostic. Only fault code being retained was faulty crankshaft position sensor (as was correctly diagnosed by a couple of very astute contributors above!).

They didn't have a replacement unit in stock so the car went back this past Monday & Tuesday, not only for the sensor but quite a few other things that I decided to get done all at the same time:

New Crank angle sensor
'B' service
Spark plug change eek: on V6's!)
Brake Fluid change
Coolant change
ATF change (I supplied the fluid - dealer supplied gasket and filter, but unfortunately two of the studs broke whilst they were removing gearbox sump cover, therefore additional labour costs were involved for drilling out and replacing all with new studs).

All told the bill came in at around £850 including VAT. I don't have the numbers in front of me but IIRC, the replacement of the crank angle sensor accounted for approximately £200 of the total.

Personally, I actually don't think that's too bad, and as far as MB Bury St Edmunds (Robinsons) are concerned, they are a very efficient and very polite outfit - so well done MB :bannana: (and I thought I could never get around to saying such niceties )

Hopefully all of that has now resolved the issue once and for all. The car has certainly been okay since Tuesday.

Regards,

 

[OzC36]

Only fault code being retained was faulty crankshaft position sensor (as was correctly diagnosed by a couple of very astute contributors above!).

Hmmm...very interesting, I'll take that onboard.

Alex,
Thanks for the very detailed and informative reply. Much appreciated and Happy motoring!