C5 2.0.Hdi occaisionally just stops.

[Peter.N.]

Its happened twice in the last couple of weeks, both times in Cornwall, happened on my way home this evening. Engine goes completely dead, after trying to glide the car into a suitable non obstructing position, try to start it, turns over but not a hint of firing, do this half a dozen times and it suddenly starts.

My first thought was the in tank pump, I switched the ignition on and off and thought I could hear it run, but it might be something else I can hear, no problem the rest of the way home.

Unfortunately my Lexia doesn't work.

Peter

[Stickyfinger]

Mine did that on my present car just after getting it. Took the EGR wiring connectors apart (down under the back of my engine ), cleaned them with spray (helps to be an Orangutang with the aim of a Sniper), problem cured.

Bet you don't have an under tray ...lets a lot of cr~p up inside.

[Peter.N.]

Undertray? Thanks, I will have a look at that - if I can find it.

Peter

[jgra1]

Big black plastic thing peter

[Stickyfinger]

If its yellow however, that kid with the Frisbee ?....you did run him over !

[citroenxm]

More cutting out HDi's and NOT being caused by the intank pumps??

Hmmmmmm Ive not sorted mine, as it only happens at high revs, heavy demands! IE: When the Fuel Pressure Ref goes over 1000 bar!

However PEter, if yours is happening at low demands, it still could be the Tank Pump starting to break up....

[Peter.N.]

Hi Paul

I don't do high revs or heavy demands, I was just poodling along at about 50-60mph when it just died, its only done it twice in the last 300-400 miles. The fuel pump would be high on my list of suspects. There was an almost complete C5 at a fairly local breakers, I think I will give them a ring tomorrow.

Peter

[BX]

Did you get sorted? Here's my thoughts. Hopefully they are of help
Probably the fuel pressure regulator on the back of the high pressure fuel pump. The original regulators have a 2 micron filter which is there to protect the needle and seat. However it clogs up over time. Remove the regulator (1 electrical connection and 2 torx screws) and check it using a powerful magnifying glass. Look for fine whiskers. Blockage of this filter prevents the regulator from allowing through enough fuel to control the pressure. The problem often happens at moderate rpm. At high rpm the output of the pump is reduced by deactivating the third piston. the filter if blocked cannot be cleaned. However it can be removed to see if the problem goes away. Some replacement regulators do not have this filter fitted. The fuel which the regulator releases is just returned to the tank.

[Peter.N.]

I haven't got it sorted yet because it hasn't happened again. I have got an in tank pump to fit as I did have a problem with one causing the same symptoms on a BMW I had briefly, I will fit that before we go to Cornwall on Saturday and see what happens - or doesn't. Thanks for the tip about the filter, I will persue that if the fault returns. I did have to replace the HP pump a while back because of difficult starting, that included the pressure sensor but I still have the old pump somewhere so will look it out.

Peter

[jgra1]

BX, would this reg cause the starting issues I am having?


?if it's blocked, then fuel wont get to rail pressure and injectors wont open ?.. when I swapped my pump recently with a second hand one, the car started fine for a week.. now its worse than before... It wont start after only a few hours without being used..

I can easily remove the part, and examine.. infact I will do this anyway asap..

John
sorry to hijack Peter

[Peter.N.]

When my pump failed it would start eventually when cold but was almost impossible when hot, the lowering of viscosity due to the temperature rise made the fuel to 'thin' to build up enough pressure to start. I did change the pressure sensor before condemning the pump but that one was on the rail not the pump, that one was screwed in not held in by torx bolts.

Is your non starting temperature related or does it depend on how long its been standing?

Peter

[lankytim]

Don't go to Cornwall again!

[Peter.N.]

Well I have to test it don't I

[BX]

If the filter on the regulator is blocked it will not cause starting problems. It will cause the car to stop without warning as it is being driven. The car can be restarted after a few minutes once the rail pressure drops. However a regulator without a filter may cause starting problems if some something stops the needle from seating properly. Never been to Cornwall so I don't know how that will affect the HDI. Been through Devon going from Holyhead to Weymouth on my way to the Continent. does that count?

[Stickyfinger]

Only if you learned to say..."myy lovererly"