D5 (2005 on) Bad Starting - first thing

[dcwales]

Sorry for not updating sooner the forum.

I have still not resolved the problem.

Since the last post I purchased a new starter and although the crank is really fast it still giving the same problem. Gone back and done another leak down test and everything looks fine. But fault remains.

I am at the point where I am thinking that i need a better scanner to ascertain exactly whats going on. Plus because of the age of the car I in two minds do I keep trying to fix it and keep spending or do I trade it in ? Really would like to get to the bottom of this as I love this car.

Since the problem only happens when the car has been left for a length of time ( 6hr Plus roughly ) and does not seem to be temperature related I doing a 180 and thinking fuel now, but guessing again.


I was going to remove the fuel pressure sensor and pressure regulator and give them a good clean . Read my Haynes manual and makes no mention of releasing the fuel rail pressure so has anybody done this on is engine or any other thoughts ?

[dcwales]

Sorry for taking so long to update this post, but I only recently found the root cause and wanted to be sure I have confirmed it before sharing as I had a few false dawns on this fault.

So to re-cap the car once left for any long period of time (say overnight ) would not start easily. Not signs of catching and when it eventually does after at least 5 secs , quite often a lot longer, there was no signs of white smoke and ran fine once started and also would start fine for the rest of the day. Only struggled to start when left for long periods, outside temp made no difference but did seem at its worse on really cold mornings.

The root cause of the problem turned to be air escaping passed the injector seat on cylinder no 1. Once the clamp was tighten the fault gone completely.

Here is how I found it , can't believe it was a simple fix and as you can see from my previous posts I tried all kinds of things and been down rabbit holes.

I actually discovered this by accident I was doing another leak off test. , I spilled some diesel around the injectors . When I was cleaning this up ( with the engine running ) I noticed bubbles in the diesel coming from injector no 1 seat . Check the clamp bolts and both were very loose. Nip them up . Fault gone completely. Of course checked the other injectors they were fine and tight. I have owned the car for coming up 10 years and none of these injectors have been touch , so must have came loose over time ? .

Over the past months trying to find the fault I have made sure that this area was really clean and checked on numerous times for diesel leaks ,but nothing was apparent , if it had not been to the accidental spillage I would never had noticed the air escaping.

Apart from the starting now so much better ( worse case takes 2 secs) I have noticed my fuel consumption has improved a bit , now averaging 48 compared with about 43 earlier . But appreciate there no science behind this just what I think I am noticing.

I don't know why this fixed it , I can only guess that when the car is completely cold the air escaping would be a lot worse and therefore harder to start and once the block and injectors heat up once the car is warmer it closes the gap a bit.

The car is a d5 euro 4 d5244t4 .

Hope is helps others sharing this..