1.6 HDI smoking and cutting out intermittently

[moopig]

Hi all

I have a 2008 Citroen Dispatch van 1.6HDI

It has recently developed a fault

When the vehicle is warm and has been driven for 10-15 minutes, when underload (pulling out of a junction or accelerating) the engine light comes on, looses all throttle, the engine starts to knock, smoke heavily, (it occasionally revs itself), then cuts out.
The fault codes stored are 'high pressure fuel pressure' too low.
If you clear the faults and leave the van 5 minutes it starts up straight away and runs with no issues.
This is a very intermittent fault, I recently took my van out for a 40 minute drive and it only happened once in this time.

I've replaced the fuel filter and done a leak off test and all injectors are ok
I've checked the electrical plug on the pressure regulator and pressure sensor and they're fine

Its still faulting though

I suspected one injector is intermittently sticking open or leaking, dropping the fuel pressure and putting unrequested fuel in the cylinder causing the smoke, knock and revving, I've had them tested and only one failed underfueling on mid range.


I was wondering if anyone else has come across this fault and know of the solution or any tests worth doing?
I've seen a couple of threads on here with very similar symptoms, but they were a long time ago with no solution mentioned?

[vincentfishing]

certainly sounds like an injector fault, i had very similar scenario but fiortunately it was a 5 cylinder diesel engine and the fault was not so intermittant, fortunatly i could drive the car on 4 cylinders and by disconnecting the injectors one at a time i pinned down the faulty injector,
in your case the cheapest way of eliminating the bad injector its to catch it on live data on diagnostics but thats going to be hard work.
I would buy a cheap recon injector and relace the no 1 inj, if fault still occurs take out recon ,replace original and move recon to no 2 injector if fault reappears move on to no3,,,, then 4
by process of elimination you hopefully find the duff injector, just depends how you are at diy injector changes ! and how lucky you are , you might get bad injector 1st time (I would start with the one that tested incorrectly)

[moopig]

Cheers for the reply, I'm glad my reasoning seems sound.
This is my plan, I've bought an injector to replace the one that failed testing.
If the fault reoccurs, I'll probably buy another injector and try it on each individual cylinder one at a time see which one stops the fault occurring.