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jackherer

Xsara VTS PH2 Fuel pressure reg 3.5 bar?

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jackherer

My 205 is not holding fuel pressure after the engine is turned off, it immediately drops to zero. In fact it is struggling to build pressure to start with, I have an emerald that primes the fuel pump via the relay for a few seconds when it is turned on and it is taking two or three turns of the key to get anywhere near the 3.5 bar the regulator is set to. And then it bleeds straight down before the engine even starts to crank!

 

If I manually activate the relay and keep the pump running it reaches 3.5 bar and stays there.

 

I took the supply hose from the filter off of the rail and pressurised it with an air line to 3.5 bar which it held for as long as I waited (1-2 minutes) so then I reconnected the hose and disconnected the other end of the rail and pressurised it there so I was including the injectors too and these also held pressure so I think I can rule out the non-return valve in the pump and the injectors seem to be closing and sealing properly.

 

So I figure it has to be the aftermarket fuel pressure regulator at fault. I know they have a bad reputation so I'm not too surprised.

 

I'm using a GTI6 fuel rail with a Sytec adaptor to allow an external regulator to be used:

 

s-l300.jpg

I could replace it with a OEM GTI6 reg but I think they are 3.0 bar? My ECU is mapped at 3.5 bar and I heard a phase two Xsara VTS has a 3.5 bar reg, does anyone have one they can check and if they are 3.5 bar can you let me know the part number please.

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Bakes100

You can get the GTi-6/VTS style FPR from ebay that is supposedly set to 3.5 bar (LINKY). However I don't have any personal experience of using one however for £17 it might be worth a shot.

 

Bosch part number seems to be : 0280160562

 

Citroen part number seems to be : 198532

 

Stuart

Edited by Bakes100

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jackherer

Thanks, I was looking at that and I'm not sure what to make of it. I tried searching for the part number on there too (0280160560) but I found it listed as both 3.0 and 3.5 bar!

 

I might get one to try but I'd prefer an OEM part ideally.

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Bakes100

It looks like the genuine Bosch ones have the pressure stamped on them, you can just about make it out on this one...

 

s-l1600.jpg

 

I seems like 0280160562 is 3.5 bar & 0280160560 is 3.0 bar

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jackherer

Sorry I missed that in your first post and just copied and pasted the wrong number from that ebay listing.

 

I just did some digging about in Peugeot and Citroen Servicebox, the 306 gti6 and early Xsara VTS definitely use a 3.0 bar reg, part number 198505. And the phase 2 Xsara VTS uses a different one but the pressure isn't specified. The part number is 198532 which is what you posted above.

 

As so many of the new ones listed for sale look fake I think I'll look for a used Xsara part.

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Anthony

I can confirm that Ph2 Xsara's are definitely 3.5 bar as I had to swap the one on my engine when I used it with the earlier Ph1/GTi-6 management, injectors etc in a 205.

 

I'll have a look to see if I kept the 3.5 bar one, but I don't recall seeing it when I sorted through the GTi-6/VTS parts.

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Anthony

Given that it's Amazon supplied I would imagine that it should be fine.

 

I suspect that it's probably one of the parts that they've heavily discounted to clear - they tend to do that for slow selling stuff that's been sat around on the shelf and certainly I've picked up some bargains in recent months.

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jackherer

It's on its way so I'll find out tomorrow.

 

As an aside have you ever seen the fault I have before? I.e. fuel pressure immediately draining away but with the supply line and injectors holding pressure? It must be the regulator surely?

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Bakes100

The only way would be is if it doesn't fully seal, try blowing through it to test it (you shouldn't be able to). What regulator are you using at the moment?

Edited by Bakes100

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jackherer

I tried pressurising it with an airline earlier, I expected it to get to 3.5 bar then crack open but air started coming out of the filler cap pretty quickly so I think it is leaking but I didn't think to blow through it to see if there was resistance, I'll do that tomorrow. I can't remember the brand either, I'll check that tomorrow. It's an Italian brand IIRC, Malpassi or something.

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jackherer

It looks genuine to me:

 

IMG_5925.thumb.JPG.de86bc448997e61f39cd0d789644c674.JPGIMG_5926.thumb.JPG.955f668431eeeef8dd946a57f71b1f50.JPG

 

 

It says 350kPa as opposed to 3.5 bar and it is made in Brazil. I noticed that the 3.5 bar reg is listed on servicebox for lots of models specifically in Brazil only, the same engines in other countries use a 3.0 bar reg. I guess this is probably related to the widespread use of ethanol based fuel in Brazil.

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jackherer

I just fitted the Bosch reg and it holds 3.5 bar exactly.

 

But only when the pump is running, as soon as the pump turns off the pressure still drops back to zero as before.

 

I took the injectors out of the manifold then pressurised the rail for a while and nothing came out of the injectors so they are sealing OK.

 

The supply line holds 3.5 bar when I pressurise it with an airline so the pump's one way valve isn't where the pressure is bleeding off.

 

What am I missing?

 

The pump seems to take a  long time to reach 3.5 bar so it might be weak but it should still hold pressure once it has made it surely?

 

I've got a brand new pump I could fit but I don't want to if it isn't necessary.

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Anthony

Is there any damage to the housing where the FPR sits?  Wouldn't take much - a hairline crack or similar - for the pump to be able to maintain pressure but for it all to leak away once the pump stops.

 

Certainly it seems to me that if the injectors aren't leaking and the feed line and pump aren't leaking, then it has to logically be related to the FPR in some way.

 

I guess you could remove the return hose from the regulator body and place the regulator into a jug, pressurise the system and see how long the return passes fuel for after the pump is shut off - hardly scientific but would confirm that fuel is leaking past.

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jackherer
1 hour ago, Anthony said:

Is there any damage to the housing where the FPR sits?  Wouldn't take much - a hairline crack or similar - for the pump to be able to maintain pressure but for it all to leak away once the pump stops.

 

Certainly it seems to me that if the injectors aren't leaking and the feed line and pump aren't leaking, then it has to logically be related to the FPR in some way.

OK I think I see what you mean, a crack that leads to fuel leaking around the regulator within the housing so there are no external leaks?

 

The housing is in really good condition, it's not battered like a lot that I've seen, I'm pretty sure I bought it from you actually! I'll give it a thorough look over tomorrow though.

 

Although thinking about it I don't think a crack would affect the Sytec adaptor I was using. It works by replacing the factory regulator and totally blocking the return line output on the rail. The return is then connected to a new output on top of the adaptor which then went to an external regulator. So even if it was leaking past the adaptor internally it would still be restricted by the regulator.

 

1 hour ago, Anthony said:

I guess you could remove the return hose from the regulator body and place the regulator into a jug, pressurise the system and see how long the return passes fuel for after the pump is shut off - hardly scientific but would confirm that fuel is leaking past.

OK that's definitely worth doing, theoretically flow from the reg should stop pretty much as soon as the pump is turned off shouldn't it?

38 minutes ago, Toddy said:

I'm pretty sure it isn't leaking externally anywhere in the sort of quantity necessary to bleed the pressure away at the rate it is dropping i.e. almost instantly. Wouldn't that have to be a pretty big leak?

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jackherer

I tried running the return into a fuel can and the flow stops as soon as I cut the pump so it seems to be behaving correctly.

 

At that point I was running out of ideas so I decided to take the pump out of the tank to have a look. Everything looks OK but when I connected an airline directly to the pump output air just rushed out of the bottom of the pump through the gauze bag thing.

 

I don't understand how I was able to pressurise the hose from the top of the fuel filter as the one way/non return valve is clearly not working.

 

It seems that kyepan had the same thing though:

 

Kyepan said: "however the bit that really confused me was when manually pressurising the fuel line from rail to pump with a foot pump it held pressure"  from this post:

So it turns out that pressurising the fuel line from the engine bay end and watching it hold pressure is not a valid test for some reason I can't see.

 

I have a brand new pump and I tried pressurising that directly and it held 4 bar for a minute or so.

 

But when I went to fit it I found it was larger than the one I had fitted to my 1992 J reg phase 2.

 

My old pump is 0 580 453 052 and the new one is 0 580 464 993. I'm not sure what I'm missing as some people seem to have used 0 580 464 993 with no issues?

 

IMG_5929.thumb.JPG.506d5414d849b1d6ee8c94a4ad64e339.JPGIMG_5932.thumb.JPG.0d0442746bfbbe67758c891dee13462a.JPGIMG_5933.thumb.JPG.201c1b3efa752d83edbd7574c77d218d.JPG

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welshpug

that is the difference between early and late vehicles.

 

i think the fuel filter may have a valve.

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jackherer

Which is early and which is late?

 

0 580 453 052 (the smaller one with spade connectors) This came out of my phase two and has a power timer connector on the housing.

 

0 580 464 993 (the larger one with screw terminals)  When I searched for this part number on the forum the only two results are for phase 2s.

 

What part number should I be looking for if I need a pump to replace 0 580 453 052?

 

If the filter has a valve that would begin to explain things but I still don't understand how that would hold 3.5 bar of air pressure from my airline yet bleeds 3.5 bar of fuel pressure instantly?

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jackherer
20 hours ago, jackherer said:

What part number should I be looking for if I need a pump to replace 0 580 453 052?

I found an old post on a 306 forum by welshpug in 2012 that says the replacement part number is 0580314075

 

http://www.306gti6.com/forum/showthread.php?id=146671

 

There is also a link to a Bosch PDF detailing the reduction of their range from 72 pumps to 7 but it doesn't work now.

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hoodygoodwood

I think a lot of our cars are suffering with fuel pump/ non return valve/regulator problems - not easy to diagnose without adaptors and gauges etc . Last time I changed a fuel filter on my 309 GTI I was curious so I sawed the old one in half to see what was doing the filtering , its just an aluminium can with a zig zag paper filter just like an oil filter . There is such a large surface area of paper I could not imagine one getting clogged and could see no valve inside .

You cant go wrong with a new Bosch FPR for £17 , have you ever seen an 8V 3.0 Bar regulator on Amazon that cheap - have never been on there .

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jackherer

That's interesting to hear about the filter, they're not cheap either for what they are!

 

The 8v reg is always very expensive, they are shared with E30 BMWs but lack of rarity doesn't seem to make any difference. I can't find any on Amazon at all, cheap or otherwise.

 

I have ordered a new pump with the part number 0 580 314 075 from here - https://www.ebay.co.uk/itm/232577297247

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jackherer

The new pump arrived from Germany, it's 100% genuine Bosch with a hologram seal with a code number to verify on the Bosch website. For £55 plus £14 post I'm very happy. It was a bit of a faff to fit as it is a different design but it does replace the original phase 2 pump in the original cradle.

 

It holds pressure after the pump goes off too, not the full 3.5 bar though, it drops immediately to 3.2 then holds but I think that must be correct behaviour, a small amount of pressure must be lost as the valve closes.

 

I still don't understand why but you can't test the one way valve by pressurising it from the engine bay end with an air line. It can appear to hold pressure when you do that but it still wont hold pressure against fuel or against an air line directly on the pump itself.

 

The engine fires up faster now too which is what I was hoping for. I still have some other issues with it though which I will post a new thread about shortly...

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Richie-Van-GTi

This thread has me thinking, there must be an ECU or injector difference when using the higher fuel pressure reg in a standard car? How can anyone bve sure they have the correct combo? I am intrigued as I may switch to the higher pressure reg when I put the throttle bodies on cams in before it gets remapped

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welshpug

to have the right bits you check the part numbers.

 

if you have enough injector flow at 3 bar you wont need more pressure if its on a mappable ecu.

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