S1 Xantia 1.9TD - Engine running very erratically

[Xaccers]

Could it be a seriously blocked mesh on the fuel sender under the back seat?

[pete the bus]

If I don't floor the pedal when starting then it will just die immediately. With the pedal down it at least tries to keep running. This is only an issue when cold, though. Once warm it may or may not start without any throttle, but usually when it does start it will be very rough and lumpy.

[citroenxm]

The pump is loosing its fuel level then and its draining out.. its running crap as its pumping the fuel and fillling up again..

[pete the bus]

@ Xac - Yes, the fuel sender filter being blocked had crossed my mind. I remember someone found theres covered in gunk and cleaning it made a world of difference to the performance...

@ citroenxm - That sounds like a very reasonable conclusion. So I need to find a fuel feed blockage or somewhere where air is entering?
What is confusing is the fact that this happened all of a sudden. One minute it seems to be running perfectly fine, and the next it's all at sea.

[Xaccers]

Replace the pipe from the primer bulb to the filter housing and housing to pump with clear silicone tubing to check for air bubbles.
Replace the leak off pipes including the end blank and pump to first injector as a matter of course.

[citroenxm]

Check the engine block face behind the pump and see if its damp or wet.. and smells of fuel.. then come back to us..

[pete the bus]

Thanks for all the help and advice so far. Will have a look over the weekend and get back to you.
Cheers guys.

[Old-Guy]

The water trap warning light comes on occasionally, but I have run about 2 ltrs of fuel out through the filter outlet and the light still comes on.

That's quite normal. The late green lady did this sometimes - for no apparent reason; just ignore it.

I think you probably have two unrelated problems: poor starting and lack of power. Based on early experience with our N reg 1.9td :-

Your starting problems sound like air getting sucked in somewhere. Replace the injector leak off pipes - they are notorious for air leaks. A 'universal kit' from your local motor factor is only a couple of quid - nothing more complicated than about 18" of the right size pipe (that you chop up into suitable lengths) and the all-important blind end for the last injector at the gearbox end. I had much the same problem, but not as severe. Eventually I replaced the apparently sound leak-off pipes; problem went away for over a year then came back. The blind end had perished but I had some of the pipe left over. Found a round-head wood screw with a plain length the right diameter, cut off most of the thread and screwed it into a short length of the remaining pipe. Job done and it didn't look like a bodge either.

If it was muck in the tank, she would start easily and after a while refuse to pick up when the throttle was floored. Your problem is that the pump is sucking a load of air bubbles that have leaked into the fuel lines while she's been standing.

As for your lack of power, first check the little pipe that goes to the 'flying saucer' on top of the fuel pump - the flying saucer is the turbo-pressure compensator, the pipe supplies air pressure to it from the (big black plastic) return from the inter-cooler to the manifold. The pipe commonly splits underneath the bend and robs the compensator of boost pressure, so the compensator doesn't compensate for turbo-pressure the pump under-fuels. The outlet from the big plastic pipe is quite small so the air flow loss isn't large - but enough to blow a mist of dirty oil (usually over the cam-cover and/or the manifold. Feel round the pipe at the bend (or just take it off and check). You don't need the genuine Citroen part, just a piece of fuel pipe the right size.

[pete the bus]

Well I've pretty much reduced it down to injector pump / injectors.
Replaced the leak off pipes (albeit with the less than perfect fitting braided ones from Halfrauds), run clear tubing from primer bulb to filter and from filter to injector pump with only a trace of tiny bubbles from bulb to filter.
I'm not sure where to look next. I found doing what I just have taxing enough, so I think it needs to be looked at by a specialist (which we can't afford).

[citroenxm]

Ive tried asking you twice now i think.. is the engine block below the pump behind the altinator looking wet or damp??

[pete the bus]

Hard to say...Everything seems to be wet or damp, especially after spraying diesel everywhere when I changed the pipes!
You'll have to go easy on me...I'm crap at this sort of thing. If I dry the area below the pump with a rag, will there be a noticeable leak if I watch it with the engine running?

[citroenxm]

Sorry bout that.. yes if can get a rag in there.. dry it all off and see...

[pete the bus]

That's OK, I'm sorry I didn't give you a reply earlier, but I wasn't really sure where you meant. So, am I looking directly at the front of the engine block, slightly to the right of the alternator and directly below the pump body? There are a couple of little hollows there where liquid has accumulated (presumably after I sprayed diesel everywhere), but also there was the remains of what looked like a rubber O-ring (although TBH that could have come from anywhere). I wish I could take a picture of where I'm looking but I don't have the means to do so.

[citroenxm]

Look to the left most.. nearest the edge of the block .. dry it all up with a good rag..

[pete the bus]

I found this on a google image search. Someone with a similar problem posted this picture:-

http://ccgi.pendulum.plus.com/fp2.gif" onclick="window.open(this.href);return false;

Would this be where I'm looking?