Starting Problems Especially After Overnight Or Long Park

[djdaz116]

hi guys 

 

I have a intermittent problem. i have had the car(c5 x7 2.2hdi 2008) for almost 12 months, and on the odd occasion(once every 6 weeks average say) it struggles to start in the morning mainly, or after a long time being parked(8/10 hours plus)parked up. once its starts it is fine, and as i use it through the day, you can start and stop it as many times as you want, it starts and runs fine and has never gave me a problem during the normal usage in a day. it is just in the morning or after a very long park. but this week it has done it twice already and seems to be more frequent.

 

symptoms - it always attempts to start on the turn of the key every time without fail, but just for a split second then dies. Turn the key to start again, and again it attempts to start just for a split second and dies. i have to do this 7 to 10 times then it suddenly starts perfectly with no smoke or anything and drives perfect.

 

i have noticed that when i do attempt to start as i explained above, yes it does seem to try and start and fire up for that split second on the turn of the key, but if after it has done its attempt to start if i was to keep the key turned in the start position, it will just continue to turn over and over with no attempt to start. it is only when i release the key, and then attempt to start again does it give the impression it is about to start for that split second then dies. like i say i have to do this many times before it starts.

 

please help me :-) 

 

Daz

[Johndouglas]

Take a reading of your battery voltage first thing before attempting to start. You should have 12.7 (or there abouts) before you turn the starter. If you have less then it's maybe new battery time.

[djdaz116]

I put a diagnostic on it. It came up with P1351 intermittent cam sensor failure. I have changed it £17. I must admit the car has got a new lease of life under acceleration that over time you don't notice the deterioration. Let's see if changes the starting problem?

[paul.h]

Possibly with the fault it was in limp mode so the performance was limited. Our C3 had a cam sensor fail and that had the engine management light on and went to limp mode.

[djdaz116]

Thanks for the reply. But no I have had no limp mode come on. Maybe because it was a intermittent fault, and not a permanent fault it did not cause the limp mode to kick in. All I know is I have changed the cam sensor and the low rev torque is a lot better and It started perfect this morning to, but I'm Not getting to excited yet as it would start ok sometimes but the signs are good. Oh and my mpg seems to be better according to the dash.

[paul.h]

Maybe it was an old fault code that was never deleted. 

[djdaz116]

Thanks for the replies. Paul this was not an old fault. For months I have kept deleting the fault and it re appears. I have had this intermittent start problem but weeks apart for months. It was becoming more frequent though. Anyway i have changed the cam sensor a week ago now. I have had no starting problems since. A noticeable increase in low rev torque and mpg is better. And no cam sensor fault.

 

Now why did I never get a limp home mode?. I don't know if it listing as a intermittent fault and not perm fault makes a difference or not. I did unplug the old sensor and it went into limp mode straight away so that worked. anyway it seems ok and runs a dream. not that it ran bad before to be honest. It goes to show how you can not notice a slow deterioration in performance until something changes.

[citrophile]

If the 2.2 HDI operates in a similar way to the 2.0 then the cam sensor is only required when starting and so it would make sense that it was an intermittent fault. Failure of the sensor does not put the car in limp mode.

If you wanted to just turn the engine over without starting it (I needed to do this when I changed turbo and wanted oil pressure before starting) then all you do is unplug the cam sensor.

Once the engine is running you can unplug the sensor and nothing will happen.

[djdaz116]

citrophile, thank your for the info. i have learnt something new, and what you say makes sense. its been a few weeks now since i have changed the cam sensor, and i have not had a problem with starting since the change. just one thing though, even though the car seemed to run ok before the change(once it started lol), since changing the cam sensor the performance is definitely a lot better, especially low end torque, and mpg has also improved. the problem is you get used to something, and its when something is changed, is when you notice the difference. i had thought for a while though, and i had only mentioned to a friend that the car drives well, but sometimes i do feel the it dont pull like a 2.2. and its only the cam sensor i have changed.