407 pressure at stop too low

siwy24 · Post by **siwy24** » 08 Nov 2010, 16:54

Hello everyone,
I have a problem with my 407 2.0 HDi
Basically when I'm stationary in traffic and want to move off it seems like if the accelerator doesent work. I need to put it to neutral and try to rev it up sometimes it works straight away sometimes the accelerator pedal just does not react!
when I had it connected to PP2000 some time ago it displayed a fault
Fulel pressure too low at stop. I laso noticed that PP2000 did not detect me pressing the clutch
Any Ideas?
thanks

spider · Post by **spider** » 08 Nov 2010, 17:06

Not sure about fuel pressure too low (the 'cause' that is)

The clutch issue is probably a faulty switch itself on the pedal, if its gone open circuit (or moved out) it will not be able to detect this.

That could actually be the cause of the other problem too in a way, certainly that needs looking at first I would suggest (the clutch pedal switch)

siwy24 · Post by **siwy24** » 08 Nov 2010, 18:03

thanks Spider
Thats what I initially thought.
On the injector pump you have a pressure regulator and my assumption is that the BSI does not detect the fact that you are trying to move off hence fuel pressure remains low. Had this problem on my car for ages now. the dealer suggested changing the fuel filter...changed it twice since they suggested it but never helped...anyone else had such problem?
If i eventually resolve this i will post an update.
Will need to look at the clutch cz my first inspection did not reveal a sensor...deoes anyone know if thre is another sensor elswhere?

spider · Post by **spider** » 08 Nov 2010, 18:21

I'm not familiar with the 407, but I thought it would have one on the pedal itself the same as some 206's do (for the same purpose)

Post by **RichardW** » 08 Nov 2010, 19:51

You need to get it on a decent diagnostic computer that will give live data read out for fuel pressure, and also the throttle position, this will then let you know whether it's the ECU or throttle position sensor giving grief.

dieselnutjob · Post by **dieselnutjob** » 09 Nov 2010, 09:42

In common with many modern diesels, the HDI will not allow you to rev the engine if you have pressed the brake pedal for more than a few seconds. The idea is that if the accelerator pedal sensor has a fault which causes unintended acceleration that the brake pedal will override it.
Also I think that the brake pedal has two switches in case one fails. This is also a safety feature so that you can always stop the cruise control even if one switch fails.
If the ECU thinks that you are pressing the brake pedal then it won't rev the engine so I would suggest that you look at
1. condition of both brake pedal switches
2. integrity of wiring to the switches
3. synchonisation of the switches (i.e do they both change state at the same time)
On my 607 one of the switches had slipped in the bracket throwing it out of adjustment
Also I have had problem with the brake pedal not fully returning to its stop which caused brake lights to come on when they shouldn't. Apparently there is a design fault on the 607 because the brake master on on the left and the pedal is on the right with a long torque tube connecting them across the bulkhead, and the friction in the tube is higher than the force of the return spring. Peugeots fix is to put shims in the mounting brackets or something and apparently it's a nightmare to do.
My solution was an extra spring that pulls the pedal back a bit harder and it seems to work perfectly.
Anyway, if your pedal switches aren't set up and working properly you will get all kinds of problems.