Losing the will to live.......intermittent fault!

[Huskyxantia]

Roller skate, haven't heard that in a while.

[Browni]

I forgot how fun little cars are to drive, my dailies are a v70 and a Touareg

[Huskyxantia]

Oh yes , stepping back to them small cars can be fun . Hope you manage to sort the cars issue

[Browni]

One of my mates has a garage so off to use it (and tools) tomorrow........I'll feed back what I find

[Huskyxantia]

Best of luck hope you find the source of the problem

[johnhuson]

If it gave out black smoke its way overfueling, if it hesitates for a second its underfuellng. Both those symptoms
point to fuel delivery. I find it difficult to accept that there are no error codes in the memory.
Have you had them read with a garage which has decent diagnostics?
Black smoke will also be there if the car has been cranked without starting and derv builds up.
If you are getting excessive grey smoke that is also overfueling.
Am not sure I have answers but it may stimulate the grey matter.
If it cuts out on hard acceleration then thats back to underfueling. I had this problem and found a collapsed air filter.
If waste gas is not escaping correctly like a blocked catalyser then all those symptoms may apply.

[Browni]

It’s been to a garage that has the Citroen diagnostic gear so seeing it’s French no it’s probably not the best there were no fault codes at all except glow plug relay which has been repaired today! Also the air filter is good!

So changed no.4 glow plug today and that’s cleared the glowplug relay fault, cleaned MAF sensor as it was pretty s**t up, checked all wiring that I could see and that looked ok! Sprayed around air intake and there’s been no searching. Let’s see what happens in the morning, been given to the end of the day tomorrow before it get weighed in for an Urban Cruiser

[johnhuson]

You need to have the car scanned again tomorrow after the changes you have made. Glow plug codes are only an indicator to a variety
of issues. A bit like a pyramid with the real issues drilling down on the scanner codes.
You are in to a spiral of changing parts in hoping you hit the jackpot? Perhaps the original diagnostic technician did not provide you
with a competent read out?
Diagbox can really drill down and find the error with a good operator who understands the process. You have assumed they did.

[johnhuson]

The diagnostic search needs to search specific areas and not accept general codes emitted by the ECU.

[Huskyxantia]

Did you test for a leaky head gasket ?

[Balazs]

Hey!

Did it solve the problem?

I have the exact same issue, for the last 30 000km / 18 000 miles.

I have got "low fuel pressure" error for 3-4 times and before that it stopped when I pressed the clutch.

I have changed

• EGR valve to Nissens, then - on a highway around 3200rpm there was a huge bang and it was blown off and now got a Wurtemberg in there

• Hand Fuel pump by the air filter

• Cleaned and checked injectors (all good, and cleaned with ultra sound

• Fuel tubes in the engine, under the air filter house too

• Fuel pressure regulator valve

• Fuel filter, air filter

• Crankshaft Position Sensor

( When it shut down it took it 12 hours to start again... also I related the clutch-press shut down problem to it)

I went with the live data, and it showed that EVERY time it stutters or "misfires" the fuel pressure drops.. The required fuel pressure lets say 1500bar, then the car gives 1800bar and trying to cap it back and swinging between 1700-1800... The other time it requires 1500 bar and starts to struggle in between 1300-1400bar. In the graph there are spikes.

Some says its the high fuel pressure pump, but I doubt it. I can go for like 300 miles without ANY issue on the highway, then 2 days later it struggles to keep up with the terrain...
I have been thinking about the maf sensor since its original + the turbo tubes are oily/sludgy on the outside.

Let me know if you have managed to solve this issue.

[MattBLancs]

• EGR valve to Nissens, then - on a highway around 3200rpm there was a huge bang and it was blown off and now got a Wurtemberg in there

Your EGR valve was blown clean off!?! Wow, never heard of that before!

I went with the live data, and it showed that EVERY time it stutters or "misfires" the fuel pressure drops.. The required fuel pressure lets say 1500bar, then the car gives 1800bar and trying to cap it back and swinging between 1700-1800... The other time it requires 1500 bar and starts to struggle in between 1300-1400bar. In the graph there are spikes.

Just reading the above: an idea, potentially the fuel pressure sensor, mounted in the fuel rail is intermittently failing and/or wiring to it intermittent connection?

I.e. maybe the pressure (i.e. pump) is fine, but the measurement of that is unreliable?