battery light flashing, hdi engine not starting

micheldeman wrote:I have taken out the injector and brought it for a test, which failed they said.

Failed injector. Its a shame they didn't say what feature of the injector was not performing correctly.

micheldeman wrote:My reasoning is that the engine was running before and not too bad either. It always started immediately, it was just that the injector seal was leaking and needed replacement.

Leaky injector seals don't usually inhibit starting, they make a bit of a mess and sound bad. You may also be down on power a bit.

micheldeman wrote:Print-out, it doesn't say much to me.

Its a bit too small to read for me. You can attach high resolution images to the forum directly using the 'Upload attachment' form below.

micheldeman wrote:If my reader is correct in saying that the high pressure pump is only producing 8bar, then there's something wrong with the HPP, but I have never touch that pump, so might air still be the problem?

If the injector has failed the test for leakoff then the pump will never be able to pressurise the common rail very much because its all returning to the tank.


I captured the cranking pressure on a Lexia system connected to a 1.4 HDi 16v (Delphi system) which would be similar to yours.


The image is the trace from the video of live data during the two engine cranking cycles (engine doesn't fire).
The video shows 2 cranking cycles with a gap between. The engine never fired.

Very well, your printouts confirm that on cranking, the hpp should generate around 200bar.
Mine (measured with the code reader) only produces 8 bar.
I don't think that any faulty injector would be able to prevent the hpp to build up pressure, at least not as low as a maximum of only 8 bar.
My reasoning is that the cause is somewhere in the hpp, probably still air leaks in the fuel system. Is it so that whenever there's even a small amount of air in the system, the hpp is not able to build up pressure at all? Similar to having air in your brake lines?

I have fitted the injector back (with a new washer) and I am waiting for a new set of return/leak-off lines to arrive.

Here's the print out of the test:

Okay, I have placed everything back, new seal ring under the injector that didn't pass the test (but that doesn't mean it's faulty or not working).
I also fitted a new set of leak off/return lines, checked everything, pumped the air out and guess, the engine started at the first attempt.

So, this is a mystery to me which we will never know what the original problem was. It may have been air, it may have been return lines that now are replaced.

I tested the pressure when idling and it is 220 bar. Much better than the 8 bar only.

Thanks for your help and I hope this thread may help others, but it's always a big guess with these diesel fuel systems, electronics etc, but to me a waste of time for replacing just 1 injector seal ring. I like to learn from things, but not like this.

Michael

micheldeman wrote:Okay, I have placed everything back, new seal ring under the injector that didn't pass the test (but that doesn't mean it's faulty or not working).
I also fitted a new set of leak off/return lines, checked everything, pumped the air out and guess, the engine started at the first attempt.

So, this is a mystery to me which we will never know what the original problem was. It may have been air, it may have been return lines that now are replaced.

I tested the pressure when idling and it is 220 bar. Much better than the 8 bar only.

Thanks for your help and I hope this thread may help others, but it's always a big guess with these diesel fuel systems, electronics etc, but to me a waste of time for replacing just 1 injector seal ring. I like to learn from things, but not like this.

Michael

Its great news that you got it running and as you say not great that you don't know why.

If you get the same problem back (I hope you don't) it may be worth jumping in with a leak-off test. You have the old leak-off pipes so it would be an easy thing to do. This will show up bad injectors very quickly.

Citroen say you should replace the injector lines each time they are removed, but I don't think anyone does unless there is a problem with diesel getting out.

The High Pressure Pumps don't usually give trouble and its the injectors that are the weaker point in the chain.

Thank you for letting us know how you sorted it and hopefully it will give someone else a short-cut to getting their HDi started after an injector washer change