Naughty, NAUGHTY C5 wouldn't start...

[Paul-R]

As per the title, yesterday afternoon the C5 wouldn't start for my wife when she was down at the shops. When I came home I tried to start it and, after nearly flattening the battery, failed so we towed it back home. Left the battery on charge and tried again this morning before leaving for work and it still was nott playing ball.

The symprtoms are that it turns over and almost fires . Sometimes it definitely has one pot fire but it won't catch.

Some background. It first did this last year when we were out for the day. I gave up trying to start it after about 10 minutes and called the RAC. When they arrived an hour later the car started! The RAC chap then put his diagnostic machine on but, of course, by that time the fault had gone and he couldn't see what had caused the problem. He suspected that it might have been the fuel pressure from the tank.

As a precursor, earlier that same day I had performed a three point turn and the engine had stalled. It had taken several churning to start the engine and it had then stopped and started without a problem several times after that.

When I got the car bck home I put the Lexia on it but could see nothing wrong with it, although that could have been my lack of familiarity of course! I decided to take the lift pump out and clean it, expecting it to be covered in gunge. It was surprisingly clean and needed very little doing to it. The car then ran for several months more until...

At Easter I was driving down through France. I had just joined the Peripherique around Paris when we encountered a trafic stoppage. The engine seemed reluctant to rev and did not respond properly to the accelerator pedal and eventually died. It wouild not restart and we sat there for several minutes while churned the engine over. There was no way I was going to step out of the car!

After some 10 - 15 minutes of intermittant turning over the engine started but it was hesitant and didn't respond properly to the pedal, almost as if the potentiometer had failed. Once I goit the car up to about 30, or even 20mph, we could keep going but when we stopped for traffic it was always a will-it-won't-it moment pulling away. At one point I was crawling along at barely tickover speed getting hooted at mightily.

Once we were out of Paris there was no problem but that was probably because I used cruise control. Even stopping for lunch and toilet visits were not a problem and it started without problem.

Whilest down on holiday I noticed a few times that the pedal wasn't causing acceleration around town like it should do but the engine didn't die. I took the potentiometer out to clean the tracks but couldn't as it is a sealed assembly so I operated the arm a few times and gave it a light 'knocking' with a wooden mallet. The car seemed OK and I've only noticed the briefest hesitation until yesterday.

Possibly relevant. I gave the car the Wynn's EGR3 treatment just before Easter and noticed that the performance seemed improved. About two or three weeks ago I was pulling away from a stop and I'm sure I felt the power go from the engine and after that the performance was very lacklustre.

So, this evening I'm going to put the Lexia on it. What, for instance, is the lowest fuel pressure that is allowable? If the fuel pump is at fault after all this would the one from a 2.0 HPi fit? Suggestions on what else to check and waht permissable value to look for.

It could have been worse; we were due to leave on holiday this evening in it. I've put the crossing and hotel off for an extra day so that I can transfer everything over to the Xsara instead.

[RichardW]

Certainly sounds like the LP pump is away - assuming it's got one! It may be fitted with Siemens injection and these don't use the LP pump - look for a priming bulb under the bonnet. Can you hear it prime at switch on? If not, try banging the underside of the tank whilst it is cranked. I guess Lexia will show a lack of fuel pressure (it needs to see 120 bar on the rail before it will start injection, but the LP side is not measured AFAIK).

I very much doubt an HPi pump will fit - just have to bite the bullet and buy a new one - GSF used to do just the insides of the pump for under a ton.

At least it's not a Picasso, which is a tank out job to change the pump on

[Paul-R]

Well it's definitely got an LP pump 'cause I've had it out to clean it! I didn't know that Siemens equipped carsdidn't have one though. Interesting but, unfortunately, no help!

I haven't had time to put the Lexia on as I've been too busy moving everything over to the Xsara so it'll have to wait until I get back.

Thanks anyway. I rather suspected it.

[Paul-R]

The car is running again.

I managed to put the Lexia on last Monday evening but, although there were several errors (most long standing!) nothing stood out as being the culprit. The fuel pressure reading showed levels over 120 bar at 180 and above. But it wouldn't start! Then I ran out of time...

Getting back to the car today it still wouldn't start and I decided to take the tuning box off. The box has been fitted for several years and the moment it was removed the car burst into life.

So, was the box causing the problem? Or did moving stuff around fix the fault?

[reblack68]

Does it have a Mitsubishi starter? They seem to be well regarded on here but the only two starters I've ever had to replace due to electrical issues (rather than mechanical wear) have been Mitsubishi items.

I suspected common rail meltdown on our C5 until I replaced the starter with a £60 one from eBay. Now it spins over really fast without drawing all the available power.

[Paul-R]

I really don't know what starter it has on. What you're saying, however, chimes with an observation I've made that the engine doesn't seem to spin over as fast as the Xsara's does. And, although it's not been a pronblem yet, I get the feelling that repeated attempts to start on the C5 would exhaust the battery quicker than Xsara.

They both have fairly new batteries bought at exactly the same time of exactly the same spec so that's definitely not a factor.