Starts from cold,rough idle cuts out after pressing throttle

[scirocc0]

I have a 407 1.6 hdi , i bought it with big end knocking and blown turbo (spares repair) , since then i've taken rocker/cam carrier off and cleaned the engine out replaced big end bearings ,turbo cartridge and injector seals

first it took a while to start , which i expected
it now idles rough, quite a bit of white fumes coming from exhaust , and sometimes goes back and forth from 800-1000 revs , then eventually goes back to steady revs.

Now the main problem is i will give it a rev to around 2000-3000 the engine sounds smooth how it should be , i then release my foot from the pedal and the car will cut out

if i try to start it straight after cutting out , it wont start it just cranks but sounds like its trying to fire, but just wont start running

if i wait 5- 10 minutes it will start again quite easy, so something must take time to change,turn off/on, or somethings pressure must change after a certain amount of time is my guess

It has a small leak from the diesel return hub/sensor type thing , however i dont think that would affect it
also Battery most likely wont be fully charged but im unsure to weather that can effect it

Any ideas or advice would be great thanks , apologies if i have not explained parts very well , first post on a forum , thank you

[Hell Razor5543]

That leak might affect it. If I remember correctly there needs to be between 200 and 1350BAR on the fuel rail. When the engine is starting the fuel pressure reaches 200BAR after 1.5 revolution. Section 6 of this document;

http://injectionpumps.redirectme.net/pumps/pdf/HDI.pdf" onclick="window.open(this.href);return false;

[scirocc0]

Hi thanks for the reply , its leaking from the leak off pipe which is connected to the hub with the fuel pressure sensor ( it think thats what it is) i will leave a link to a picture for an example

http://thumbs1.ebaystatic.com/d/l225/m/ ... cedZkQ.jpg" onclick="window.open(this.href);return false;

i thought it wouldnt effect it as ive seen videos of people doing leak off tests using bottles instead of the usual fuel return