laguna diesel, idle speed eratic at low revs .

just took my laguna 03 diesel to a garage... they only had a snapon computer not the renault tester ,,, and faults on the screen came up as

crank shaft sensor

also something to do with fuel pressure /maybe even pump i think...

and a couple more things which i dont remember.



the car basically starts fine without fail everyday

on long non congested runs ... no real probs

but after sometime in heavy traffic , stop/go stop/go queing at traffic at junctions and the such at peak time and not really moving.... the idle speed starts fluctuating



dropping from 800 odd revs to perhaps 600 and then back upto 800 odd even 900,

if i leave the accerlator alone, the revs will keep fluctuating even more , until the engine eventually cuts out.

i can start the engine again easily enough but the fluctuaing revs more or less kick straight in,,, i usually just switch the engine off for half hr or so ... and then no problems ,,, revs dont return...... not until maybe i hit some heavy slllooooow moving traffic and its lots of clutch and accelator movement.





long straight runs seemling no issue





i read somewhere of someone else having similar problems .... turned out to be the fuel pressure valve ....





anyone anything similar.





p.s , the guy at the garage changed the crank shaft sensor this morning ... still same problem.







any mechanic in north kent/south east london who can rectify this for me would be very appreciated.