406oc.co.uk

Hi all, I am new here but am wondering could anyone help me diagnose a problem.
I have extremely intermittent revs and power. I can go to start the car and take off and will die from lack of power. It will get sudden bursts of power for a few seconds that would make you think the car was fine. I can hear the turbo running so i think that is not a problem. The problem started when it got sluggish doing 70mph on motorway but now it is hard set to idle, sometimes dying. Is there anyway can diagnose myself and or fix. If you need anymore information just shout.
Thanks in advance,
Eamon

I have replaced the fuel filter and also tested the air flow meter. Problem still exists. Can anyone help? What can or should i check next?

Hi, has this problem occurred before or after replacing the fuel filter?

Have you checked the clip on the throttle cable, if this falls off then the cars acceleration is a bit hit and miss. If the clip is there, make sure it is tight up against the throttle cable housing - then do a throttle reset which is;

Ignition on - throttle down to the floor for 10 seconds - release throttle and ignition off - start the car without touching the throttle.

Is your Hdi a 90 or a 110, as this will help diagnose possible vacuum leaks.

Kelv.

Hi kelv,
Thanks for the reply, The clip is present and i tightened it and did a throttle reset, to no avail.
It is a hdi 90. As per a mechanics request I replaced the low pressure fuel pump in the tank but problem still exists.

Thanks Eamon

The pressure regulator on the HP pump causes all sorts of problems, usually because the filter is blocked but I have found them almost impossible to clear.

Peter

i had this fault and and it was the thrat sensor as that where small flakes of mettal build up in the greas which then gives a bad reading so lave the fuel system for a bit or at least till you and put a new throtal sensor on

Yes I have had that, its because the lift pump in the tank is failing.

Peter

Hi peter, could you describe where the hp fuel reg. is please? or a picture if possible. I have replaced the in tank pump already and was considering the throttle sensor next but i have a spare injector pump from a good engine here also so I am try that next. Just so long as I am sure what i take off is correct.
Thanks
Eamon

Hi Eamon

Its on the end of the HP pump which is situated behind the cam belt housing, looks like this:

http://www.ebay.co.uk/itm/CITROEN-C4-C5 ... 4d20371ddd

You will probably have to remove the fuel filter to get to it but that's not difficult. The regulator is held on by two torx or allen screws and a connector.

Peter

Thanks, I thought thats whats it was. I toke it off and checked it. Started rusting under the seal at the edges. Waiting on a new seal now before I can fit another to see if that solves the problem. Am I correct in thinking the is another regulator on the rail? and is this known to give trouble?
Thanks
Eamon

Also mine had 3 torx bolts holding it on. I thought it was unusual as most have 2 as in the picture you showed.

There is no regulator on the rail, just the rail pressure sensor. These run at up to 1350 bar BTW.