Citroen C5 2006 2.0.hdi starting problems

[gingernut]

Hi

My c5 refuses to start. The engine turns over but doesnt run. My local garage ran diagnostics (not lexia) and found no fault codes. They tried replacing the crank shaft sensor and it still wont start. They tell me fuel is getting to the injectors and are now at a loss as to what is wrong. I have just got a lexia system (and a geriatric laptop to run it) and am planning to get the car home and see if I can sort it out.

The car has never had starting problems before although it did occasionally cut out when at low revs but would always restart. I had driven it to the garage for its MOT and it was there that it wouldnt restart. The only thing that happened that day is that it was left outside with the drivers window open while it was waiting to be tested and a heavy rain shower came along. It was after that that it refused to start. Not sure if that is relevant but I mention it for completeness.

I plan on checking the fuel filter for metal fragments from the lift pump. Im told there is a gauze just before the hp pump so Ill check that too.

Any ideas of things to check? I like this car and really dont want to junk it.

[CitroJim]

Can you hear the lift pump running when the ignition is first switched on? If silence then despite what the garage says then the lift pump needs looking at...

How did they check that there's fuel at the injectors? It's not easy (or safe - bloody dangerous in fact) to do with any degree of accuracy on an HDi engine. That there's fuel at the injector may well be inconclusive as it may not be sufficient or of a high enough pressure to allow a start...

A Lexia will surely give you some useful data as the engine will fail to start if the engine ECU does not see sufficient injection pressure being generated for instance...

It'll also fail to start if the cam or crank position sensors are faulty... These problems may not show up on a generic code reader... A Lexia session in such cases, where you can look at live data, is essential to diagnose problems like these..

[gingernut]

CitroJim

Many thanks. Im not sure how they checked the injectors but I share your suspicions about the lift pump and the limitations of generic code readers. Ill have a better idea once I get the car home and get lexia connected.

[Gibbo2286]

I doubt you have lift pump trouble on a 2006 2.0 HDI, most don't have the in tank pump they have a rubber bulb primer and the lift pump is built into the main pump under bonnet system.
Air in the fuel rail might be your problem you need to be sure it's bled right out up to the injectors, try a blast of easy start through the intake it will sometimes be enough to get it going and clear out the air.