C5 intermittent starting problem

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C5 intermittent starting problem

Post by RSimmonds » 30 Aug 2014, 15:35

Sorry this is long but I want to make this as clear as possible as I have read similar problems on forums but they turn out to be different and none of those solutions have helped.

My 2003 C5 Exclusive 2.2 HDI was very reliable till November when it was rear ended while parked. There was £1600 damage and since the repairs it been one problem after another. Since March she's had a major service, a new timing belt, been fitted with pads, disks, callipers all round, suspension pump and the drivers side floor and wheel arch (which exploded soon after the suspension was fixed) and now we have an intermittent starting problem. It's already cost us £150 in Lexia diagnostics that show nothing because the car starts when it's at a garage.

Normally I put the key in hear the mirrors open and both the suspension and fuel pumps whir, the car fire's easily and starts first time however occasionally I get in the car, can hear the suspension pump, put the key in hear the mirrors but not the fuel pump priming sound. When this happens I turn the key the car turns over and sometimes it even fires but then it immediately cuts out. Sometimes I can leave it a bit and it seems to correct itself on its own, at others it just refuses to start until someone has a fiddle with it. Hubby has got it going a few times by seemingly checking connections but has no idea what fixed the problem.

At the moment it's been sitting on my drive in Loughborough a couple of days refusing to do anything but I am loath to call out the rescue and get it delivered to the garage with the Lexia because the last time I did that it was rolled off the recovery vehicle pushed into the garage and soon after we left one of the garage lads got in and without thinking turned the key and it fired perfectly and ran beautifully for the next two weeks.

Can anyone offer us any insight or better still a solution other than dump the car and get another one since my state pension just won't stretch to that. It's such a shame when she works she is the most comfortable car I have ever driven but just lately she has left me stranded in the pouring rain so many times it's fast becoming a nightmare :(

My C5 has two fuel pumps one in the fuel tank accessed under the passenger rear seat the other in the engine; it doesn't have a priming pump. Also In April we had the fuel filter replaced as part of the service and they put Redex and STP fuel cleaner treatments in at the same time.

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Re: C5 intermittent starting problem

Post by Hell Razor5543 » 30 Aug 2014, 16:27

First, welcome to the forum. However, I cannot help with your problem (I only have theoretical knowledge, gained from this forum), apart from to sympathise. Intermittent problems are the worst sort, hated by all engineers. Based on part of what you say I would be inclined to check the fuel pumps. I would also suggest you have a look on the link I will pop up, as a lot of members have Lexia systems, and would be willing to help;

http://www.frenchcarforum.co.uk/forum/v ... 19&t=29178" onclick="window.open(this.href);return false;

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Re: C5 intermittent starting problem

Post by myglaren » 30 Aug 2014, 16:49

As James says, check out Lexia owners in your vicinity in the first instance.

As you say the car was rear-ended before the start of your problems and the nature of the problem my first suspect would be an intermittent fault with the in-tank lift pump - it is a fairly common problem and may be a result of the collision.

Listen carefully on each use and see if the pump actually does run. Depending on how happy you are getting involved in oily bits, you might try disconnecting the feed from the tank to the fuel filter and directing the pipe into a large clean container, turn on the ignition and check for a good flow of fuel.

There have also been instances where the in tank strainer becomes blocked with some rather disgusting rubbish allegedly caused by algae growing in the diesel - probably depends on how much use the car gets.

Also, welcome aboard :welc:

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Re: C5 intermittent starting problem

Post by BX » 31 Aug 2014, 00:42

I have come across a similar problem once before. It did not include a rear ending though. The problem was a poor connection on the wire for the low pressure pump. Sometimes it didn't make contact and the pump didn't operate. The problem was on the multiplug connector in the under bonnet fuse box. The wire is either a pink or salmon colour if I remember correctly. I have checked the manual and it is pin 11 in the 16 way grey connector. Unplug this connector from the box and check very carefully for signs of heating or melting plastic. Also look carefully also at the pins in the socket in the fuse box for any sign of pin 11 being discoloured. There are at least 2 cheap fixes if this is your problem.

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Re: C5 intermittent starting problem

Post by Filberton » 31 Aug 2014, 11:26

I had exactly the same as BX described on a '53 plate C5 but mine developed to doing it when running (disconcerting!)
The low pressure electric pump feeds to the mechanical high pressure on the engine. So, no low pressure pump, no feed to the high pressure so the common rail pressure drops and ECU shuts down injectors. My problem was corrosion on one of the ,vplugs to the ECU which then burnt out. Suggest BX is right, an easy fix is to remove each of the multi-plugs in turn, check and clean contacts (Maplin do a good contact cleaner - plug and unplug them several times to aid the cleaner - I would strongly recommend proper contact cleaner NOT WD40 - Servisol is another good cleaner if you can get it.) - Don't forget if you have been wise and disconnected the battery to re-initialise the ECU and BSI correctly.

If you can't hear the pump, you are still left with the issue: is it the wiring or pump? I have before put an LED lamp on a temporary lead into the car so when the pump does not run you can see if it is getting power - this will tell you if it is pump or wiring at fault.(intermittent are a pain as they misbehave when you don't want and perform when you check. If you have had it on a Lexia I would have thought you might have an historic fault code recorded for low common rail pressure (but not sure if ECU monitors this until engine running). [Lexia guys on this forum may know when it looks at this sensor; I know some sensors are not checked until the engine has run a while]


Re: C5 intermittent starting problem

Post by Northern_Mike » 31 Aug 2014, 11:34

My 2.0 HDi C5 which I sold to my brother about 2.5 years ago developed a habit of cutting out in inconvenient places and sometimes refusing to start. Eventually it died altogether in the centre of Rawtenstall.
It was the in-tank pump. Whacking it with the wheelbrace had it going again, and since cleaning the filter of algae crud, and cleaning the connectors, the same pump is still working fine. I've told him to replace it of course...

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Re: C5 intermittent starting problem

Post by RSimmonds » 02 Sep 2014, 14:49

Hi all

I did look for the nearest Lexia in the group but that was either in Hinkley or the other side of Nottingham and the car was immovable so we had no way of getting it there and it didn't seem right asking someone to drive over to us from that far off.

Instead the local car electrics company with the Lexia came and put it on the system but aside from a fault in the passenger door module and another in the sunroof module it did not show anything.

However he did some other tests and they showed there was no power getting through to the lift pump so he checked the wiring and fuse box and yes one of the pins in the plug has melted so BX thank you - you were right.

At the moment he has taken the top of the fuse box so that he can rewire the connection to by pass the plug as he said the alternative was to get another plug from a breakers yard and switch plugs which could be problematic.

I am hoping a by pass was one of your solutions; the whole thing will cost us around £100 so I guess reasonable given he came to us. I just hope this fixes the problem and that's the end of it as it would be such a shame to have to get rid if the car. I know that people slag off Citreons but the car is such a pleasure to drive and she really has been a great car before all this started.

Thanks for your help and sugestions

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Re: C5 intermittent starting problem

Post by RichardW » 02 Sep 2014, 15:27

This is not an unknown fault - see http://www.frenchcarforum.co.uk/forum/v ... =3&t=43775" onclick="window.open(this.href);return false; And the post at the bottom by wheeler (who is a Cit Tech AFAIK):

"Thats exactly what your problem is, pin 11 is the output to the fuel pump. You can get replacement terminals (Citroen part number 6542TV) Not expensive but you may need to buy a bag of 20. You can remove the terminal from the block, cut the old terminal off & fit a new terminal with a new piece of wire so the original is not streched. Also clean the pin in the fusebox with a small file."


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Re: C5 intermittent starting problem

Post by BX » 02 Sep 2014, 16:34

The connector going to the engine harness on the 2.0l also has a pink wire in it the same colour as the one on pin 11. These 2 are connected internally in the BSM. The one going to the engine only carries a few mA as against 10A for the fuel pump. Verify that the 2 are connected either by using a test lamp or an ohm meter. You can then join the 2 wires together.
Option 2.
The pin beside pin 11 is spare and is the same connection and so can be used with a connector retrieved from a scrapped car

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Re: C5 intermittent starting problem

Post by RSimmonds » 03 Sep 2014, 15:41

Thanks all especially BX as your replies have been spot on. Hopefully car in process of being. One last question we are thinking of buying a Lexia clone since our nearest is around 25 miles from us - if we can get one, and get it working we would be happy to use it to help anyone local so if the person in charge of the list reads this I will let you know when we are in a position to do that.
I can find clones on line for as little as £39.99 going up to over £375 for a second hand genuine one but most of them are in Hong Kong or China which is a long way if it doesn't work.

However I have found one a company in the UK advertising them, has anyone on here bought one from a company called JJDiagnostics and if so at they any good, if not where is the best place to buy oneCar as I personal experience has left me a bit wary of EBay

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Re: C5 intermittent starting problem

Post by MikeT » 03 Sep 2014, 16:03

If you want a fully-functioning clone, buy from JJ. They are dearer than many but will be sourced from a reputable cloner using the latest and original parts where necessary and flashed with the latest firmware, (especially important if you intend to use it mainly on your C5).

I'm sure cheaper can be had but unless you know exactly what the differences are, it's pot luck buying from a cheaper source. The £40 one I bought from china could be it (it is the "C" serial number version and runs the latest Diagbox 7.59), or it could be lacking, I've yet to test it on all models but for now, it does what I want it to do.