C5 HDi Fuel Pressure Regulator Testing

[xantom]

I've had 2003 Series1 C5 HDi for over a year now. It's a good car in lovely condition and, although a Xantia fancier generally, I'm well impressed with the big C5 estate. It isn't working at the moment though. It just won't start. I've been running it on about 1/3rd mix of vegetable oil as I read this was okay. It's been running beautifully like this for about 8 months and in that time has had a non-start incident shortly after adding the veggie to the tank (still maintaining the 2:1 mix). This was cleared by a garage courtesy of Green Flag. The garage didn't know why it started when they were checking it out, it just did. Because of that, I think I might have gunked up stuff. The veggie tends to clean out the pipes. This time it did the same non start after my adding the 1/3 veggie to my 2/3 full tank of deisel. I paid a nice man with a van to come and diagnostic it on my driveway and a few other fault notifications happily cleared but the fuel pressure was consistently low, way to low for the engine to get underway. I've scoured the forum and on the basis of what's there have removed the FPR. I'm currently soaking it in a jar of petrol in case it has just got gunked and stuck. Does anyone out there know if I can at least test it mechanically for correct movement, assuming the probe is meant to move? It doesn't move right now but should I be able to press the probe in and out a bit? I'm going to let it soak most of today and then re-insert it and try the car again. I have read that it might be a blocked filter and, from the description, my FPR has the silver tip to the probe that is the filter (is that correct?). Some mention has been made of grinding off the filter. I'd not be too keen on that as if the filter's there it's probably to protect the injectors but as a diagnostic tool I might try it if the soaking fails. That way, if the car works I'll know what the problem was and get a replacement. Hope you guys can help. Thanks.

[Miguel]

I've had 2003 Series1 C5 HDi for over a year now. It's a good car in lovely condition and, although a Xantia fancier generally, I'm well impressed with the big C5 estate. It isn't working at the moment though. It just won't start. I've been running it on about 1/3rd mix of vegetable oil as I read this was okay.

It isn't ok. You could have gunked up or damaged any (or all) of the fuel system. HDi engines SHOULD NOT be run on any mix of veg at all.

[Stickyfinger]

No expert but.... I have seen the question asked many times.....but I have never seen it to say it is OK with any HDI engine, always a big SCREAM of No

?? Where did you see/get that advice ?

[CitroJim]

It isn't ok. You could have gunked up or damaged any (or all) of the fuel system. HDi engines SHOULD NOT be run on any mix of veg at all.

Absolutely so and in addition the veg may have gummed up the piston rings which can lead to lowered compression and a non-start. This is due to the veg polymerising (turning into plastic - think of a well used chip pan) around the piston. When this happens and ring seal becomes less than good the veg can get into the sump oil and wreak further havoc and damage.

Veg use in DI engines like the HDi should never be contemplated. Damage can be extended well beyond the fuel system.

Confine its use to XUD engines with Bosch pumps. The only other known OK PSA engine to run it on is the DK5 2.5TD XM engine.

[xantom]

Wow! Thanks for the speedy responses guys. Bit sobering though. I didn't come up with the veggie idea myself, honestly, I did a fair bit of internet reading first. I'm quite taken aback and not a little worried by your responses so I'll re-internet the concept and let you know where I got the info. Basically, I read that not only was it not as dogey for HDi Citroens, as I'd previously believed, but that even Citroen don't invalidate their warranty if you run up to 30% veggie and as French deisel is aboaut 10% bio anyway I was easily convinced. If this isn't true it's another evil from the internet. Having done it though, I'd better try to resolve it. Any ideas on physical testing/proving of the FPR, assuming I haven't killed it yet. Thanks.

[CitroJim]

There's a huge difference between veg and bio diesel. Bio diesel is certainly made from veg oil but it undergoes a significant and complex chemical process to remove the glycerols (soaps essentially) from it in a process involving heat, methanol and caustic soda called transesterification.

Certainly 10% bio in mineral diesel is fine but this does not mean 10% straight veg is for the reasons given...

Hopefully if you give everything a good flush out with straight diesel and replace the fuel filter all will come good. Certainly hope so

Hopefully, with the FPR being well downwind of the filter it'll be OK.

Let us know how it goes please.

[Gibbo2286]

I'm a bit surprised at the comments, my pal has been happily running his Peugeot 2.0 HDI estate on veg oil mix for more than five years now, mileage is approaching 280k without any ill effects.

[CitroJim]

Does he take any special precautions Gibbo?

What's his driving pattern/style?

I'm intersted to see if there's any mitigating factors that might explain his success.

[lexi]

Maybe in higher temps and with low oil ratios, some owners are getting away with it.
Surprised that it does not give issues in colder weather. Some put petrol and similar in along with oil/derv in low temps.

I always thought that in tank fuel pumps would have problems pumping a slightly thicker mix of veg/derv in the cold.

[Gibbo2286]

Does he take any special precautions Gibbo?

What's his driving pattern/style?

I'm intersted to see if there's any mitigating factors that might explain his success.

I'll have to ask him Jim, I know he's fussy about the percentage of the mix but haven't discussed it much further . He was trucking, delivering to Tesco and had a ready supply of chip fat from their restaurants, a home made refiner/cleaner and gives the stuff a final filter through coffee filters.

I've not tried it myself, not worth the hassle for the amount of travel I do nowadays.

[wizaird]

Hi folks, regarding running your vehicle on BIO DIESEL I can confirm I ran my 2003 C5 2.0 HDI on B100 or 100% bio for 3 years and covered over 60000k miles with only 4 issues arrising from contaminated fuel; self inflicted (lol) just replaced filter and cleaned the fuel pump .......30 minute job .......The worst problem was from the vehicle itself and split vacuum pipes and a dodgy MAF sensor. replaced these and hey presto ...she was like a new car again !
Only got rid of it the other week due to new bearings required in the rear swinging arms and other bits and bobs.
Now I have a newer 2006 model and this one needs all its niggles sorting .....check my other post.
This has required a new injector fitting after a solenoid failure and now I have an acceleration issue with the ESP / ASF DEPOLLUTION WARNING FAULT coming on !
Also get an intermittent SERVICE illumination and beep when I attempt tu use crusie control ...sometimes it allows me sometimes it doesn't .............give me my a 2003 model any day !

regards Dave

[xantom]

Hi Guys. Not much progress on my no start problem. Replaced the Fuel Pressure Regulator but no change from that. Primer pump is working. I intend now to assume it's a crankshaft position sensor fault and/or a camshaft position sensor fault, neither of which registered on the diagnostic I paid for but which other folk on posts have said was an un-notified fault for them. I read from one post that the sensor was at the 10 o'clock position near the crankshaft pulley. I can't find it there on my 2.2 HDi. Does anyone know it's location as not having the car is complicating my life a bit. Thanks.

[citronut]

if you give me your car engine code i will look on my Auto data software tomorow, as it gives component location

[xantom]

Malcolm, thanks for that offer. I've been out to the engine but I'm not sure I've located the codes necessary. Here's what I have. On the Head there are some embossed numbers: 0265 15 16 and on a plate stuck onto the upper cambelt cover are the following: 4013047, 10DZ18 and 95A4HX (that might be 9SA4HX). Hope these are the numbers.

[RichardW]

Service.citroen gives an indication of the locations, 10 o'clock for the cam sensor is not far off, top of the flywheel for the crank sensor. You really need to get it on a Lexia though to see what is going on - you can't really poke and hope with an HDi.... If there's no one nearby (http://www.frenchcarforum.co.uk/forum/v ... 19&t=29178" onclick="window.open(this.href);return false;) then they can be bought relatively cheaply, and there is plenty of knowledge on their installation and use now. Was there any sign of stuggling to start before it refused? How is the battery - C5s can be fussy about batteries that are a little under par.