What is this ?

[Muttly]

Trying to identify this, it fits in the alloy housing pictured which is above the HP pump on the 1.5HDI where the fuel filter used to be sited..check valve? Been googling all afternoon..

[MattBLancs]

Please sir, may we see the other side?

I'm going to guess "vacuum reservoir". Where did the pipe connections lead?

[mickthemaverick]

Does this give you a clue?

https://www.ebay.co.uk/itm/316264419792

[MattBLancs]

Does this give you a clue?

https://www.ebay.co.uk/itm/316264419792

Hmmm, I'm not sure if it does, Mick!

I googled "dv5r fuel filter" and get different looking thing-a-ma-jigs!
E.g.

Google result (actually another eBay listing)

[mickthemaverick]

The reason I posted that ebay offering Matt was that, besides looking the same, it is for a 1.5HDi which matches the car in question. I wonder if the designs differ according to the engine they are fitted to?

[MattBLancs]

The reason I posted that ebay offering Matt was that, besides looking the same, it is for a 1.5HDi which matches the car in question. I wonder if the designs differ according to the engine they are fitted to?

Yes it's a good visual match - I didn't explain myself well - I wonder if the vehicle dismantler has identified it incorrectly.

[PaulC5]

On the other related topic about this part I posted this reply. Also if it has been put in instead of the fuel filter then there seems to have been a bodge.

I did a google lens search (right click of mouse on the picture) on your picture and it came back with something very similar on ebay listed as a fuel tank valve with part number 9831640680 https://www.ebay.co.uk/itm/277130841856 It could well be a check valve as you suspect.

[Muttly]

Does this give you a clue?

https://www.ebay.co.uk/itm/316264419792

Hmmm, I'm not sure if it does, Mick!

I googled "dv5r fuel filter" and get different looking thing-a-ma-jigs!
E.g.

That filter is for cars with the main filter above the HP pump. My Partner has its 'main' filter beside the tank. Mick may be correct in that this small unit I posted the picture of appears on ebay as pt no. 9831640680. Fuel tank valve?? Or it may be a last chance filter..either way I think I need to replace it before the HP pump..?

[Muttly]

https://www.ebay.com/itm/357980184072

Another plausible description..?

[Muttly]

https://www.ebay.com/itm/135172450376
Thats the fella..£32.34 from Arnold clark. They have it as a damper.

[Mihael_M]

These are all ads from sellers who gave new names for that part: Fuel Filter (wrong), Damper (maybe), Valve ( maybe). But on this page (https://rrr.lt/en/used-part/att41102-98 ... -regulator) it seems that finally the right name is associated with the function. I don't know how it can regulate the pressure, it seems to me that it is rather a non-return valve that prevents the fuel from returning back. In this problem, that part is probably defective and should definitely be replaced, because that will determine if it is defective.It is cheaper than the HP pump and is easy to change.

[Muttly]

So after replacing a damaged return connector from the hp fuel pump by the cam cover. The car wont start. I replaced the damper, no change. Replaced the fuel filter and found the smaller of the two seals to be missing !.. Fitted new filter and bled it and the feed to the HP pump, still no start. Replaced the HP pump, water pump and timing belt. All back together, followed all the pump on/off cycling and it still wont build rail pressure. LP flow to the HP pump fills a 1ltr jug in no time so confident the LP pump is good. I just cant get Flow from the HP pump. I'm starting to get pissed with myself as I've done plenty engine work on petrol and diesels but this is seriously annoying now. Lexia says the ecu is not locked. Fuel pressure is still at 8bar, I do hope that drops a bit when and if the thing starts.. The only thing I may have done was not using a pin to time the fuel pump. My understanding is it doesnt need timed like the DV6 engine..
I cant think of anything else.....hell-p

[RichardW]

What is on the live data? It needs to see crank signal, cam crank synch, and then fuel pressure above 180 bar before it will allow injection. I don't know on the 1.5 if it needs to see low pressure before it will build HP pressure. Presumably there was some earlier fault that upset starting / running?

[Muttly]

Just retimed the pump and tried bleeding but nothing. Setup pump as per this
about 4m57s in
@RichardW I originally had P008B fuel low pressure too high with limp mode after about 2mins running cold or hot.. Diagnose Dan has a tech notice on YT about this same fault. I looked at the LP pressure which according to others data, should be around 5bar. I had 8Bar. I measured the flow rate during cranking and it was no where near the 500ml or so that a 'healthy' system was said to produce. That led down the path of LP system parts, ie the fuel filter/DIaphragm(pictured earlier) and ultimately to the HPFP. Having replaced this I have no rail pressure and no start obviously..I've tried bleeding the thing to death but to no avail. I might try a rail pressure sensor...? WDYT?

[RichardW]

Is it reading 8 bar all the time? If you key on and let it prime then sit does the pressure drop? Might it be a fault with the LP pressure sensor or wiring? I don't know much about these later systems with the LP pump and what the ECU is looking for to allow a start.