406oc.co.uk

Hi, can anyone help me please.

My 406 HDI has an intermittent fault, its happened periodically over the last couple of years. When I try to start it, it might take 6 turns of the key to get it started. Then it will be fine for months then it will do it again.
It did this last Friday, but eventually it started, then on Saturday it refused to start, called out breakdown people the guy connected a battery booster and it started 1st turn of the key, when out in it stopped and started it several times all ok.

Sunday I went out early just to see if it would start - 1st turn of the key it fired up, then a few hours later when I was going out, it wouldn't start at all, so i left it until Monday got breakdown out again connected battery booster - started 1st turn of the key again, so I went to my local mechanic who checked battery which is fine, also he connected an analyser to it after a while it came up with an “intermittent fault 1614 Sensor supply short to earth”.

I have started it several times since and again this morning - no problem, but i'm scared to go out in it incase it won'y fire up again.

I just can’t understand why it fires up when a battery booster is used though ? If it was a sensor at fault, surely it wondn't fire up with a battery booster

Has anyone else had this problem ?

Any help would be appreciated

Sounds to me like the lift pump inside the fuel tank. These can play up intermittently and not supply fuel to the second high-pressure pump on the engine. Starting off the battery booster may have been a fluke at the time.

When you turn the key to 'ignition' you should hear a faint hum under the rear seat bench (this is the lift pump priming) if it sounds grumbly and with a sort of hammering sound then it is worn. The old trick when you get stuck was to thump the fuel tank underneath with your hand to shock the pump into life (I got away with that a few times but that is usually not far from it failing completely).

This is not a diagnosis but a possible reason for the problem you describe, I think we used to say it was also related to how much fuel was in the tank too.

Young master welton is probably right about the lift pump and his suggestions for listening out for the pump are good advice.
I suspect the P1614 code is simply misleading - a generic code reader probably won't differentiate between an active or historic error code, so it's probably not that, but....
A search for P1614 reveals it's likely to be an immobiliser glitch.

If I happens again, check the lift pump as welly suggests, also check that you get the warning tone if you open the door with the key in the ignition but turned off. If you don't the car isn't 'seeing' the key transponder. Taking the key out and re-inserting it may cure this, or possibly the receiver, (which fits around the ignition lock), is loose. Tapping the housing may help.

Thank you so very much for taking the time and trouble replying to my problem it really is appreciated.

I had a problem with the lift pump back 2011 all as you described and had to have a new fuel pump.
I will check this again though the next time it happens, because the replacement lift pump is now 4.1/2 years old now, also I have ½ tank of fuel so I don’t think its fuel shortage.

The other thing I’ve been considering is the stop solenoid – in the Haynes manual under fault finding that’s one of the reason s listed for the engine turning over but not starting.

HDi's don't have stop solenoids.

Hi Doggy thanks for your reply
My 406 doesn’t have HDI on the boot next to the 406, but my reg document does say 406 HDI and I’ve seen something that looks like the stop solenoid – see photo it looks like solenoid mounted on top of the fuel pump, please correct me if I’m wrong.
Any help would be appreciated

I think you're looking at the pressure regulator on the HP pump. The picture's not wonderfully clear, but I'm fairly sure I can see the fuel rail at the righthand side, (it's an aluminium casting about 9" long that has 4 metal pipes leading to the injectors). A 1.9TD won't have this, but a 2.0/2.2 HDi does.
Your registration document should tell you as well - you either have a 1997cc HDi or a 1905cc XUD. The latter has a stop solenoid, but doesn't have a lift pump.

Hi, I'm pretty sure you have the Hdi engine - I can see the mounts for the rubbish engine cover - if its the orange plug in the photo that you are asking about then I think this is the 3rd piston sensor.
The 3rd piston is activated to increase fuel pressure when in demand, can also be activated by the ECU ( I believe ) when cranking the engine to boost the fuel pressure.

Hi again, Thanks to all of you for the information you have given me.

If there is no stop solenoid, then what stops the engine when I turn the key to the off position ?

Thanks in advance for any help.

The injectors are controlled electrically. When you turn the key off, the ecu stops 'firing' them.

Thanks again for the info.

Yesterday, I started it around 6 times, and then sprayed the various electrical connectors on the engine with RS switch cleaner as they were quite grubby and just to be sure put the battery on a trickle charge for around 4 hours.

This is a strange problem. I’ve been out in it today, done around 20 miles, stopped and started it 6 times and it’s fired up 1st turn of the key each time.

Hopefully it will start tomorrow.

Hello to everyone, I’ve woken up with a serious dose of manflu today,

So I haven’t been able to try to start my car today.

Anymore suggestions would be greatly appreciated.

Thank you in advance.

Barely-diluted whisky masquerading as a 'toddy' and lots of sympathy?

Thanks Doggy - it might taste better than Shell 'V' power diesel and make my car more reliable

I had exactly the same problem. For months, everything would go fine. But occasionally, the engine would just not start. At the key turn, the starter motor would turn and drive the engine, but it just did not fire up.

As time progressed, this would happen more and more often.

In the end, I got stuck at a filling station. It wouldn't start, even after half an hour. A "helpful" customer offered me to spray some "easy start" spray into the air inlet. While he did this, I started the engine. It fired up allright, then a heavy knocking sound then it went into very high revs. It kept on running even when I removed back the ignition key. After a few seconds the oil filler cap popped out and a grey plume of smoke came out the oil filler hole. Engine gone beyond repair...

Mine was a 2001 HDI 90.