Xantia Rough Idling/Hunting when first started

coopertron · Unread post by **coopertron** » 22 Mar 2008, 20:27

Hi all,

I have a 96 P Reg Xantia 1.9TD which in the last week or two runs quite rough when first started and left idling.

It only seems to be when first started up from cold, as it doesn't do it when warm.

When first started it starts fine on one cycle of the pre-heaters, but then hunts up and down the rev range, from 900 - 1100rpm. At this point, it seems to throw out a fair amount of smoke, and it normally doesn't really smoke at all.

If you drive a few hundred yards down the road, then it goes away. The car does still drive ok as well.

I was thinking this might mean that some or all of the glow plugs have had it, or at least hope so and it's nothing more serious....

Unread post by **CitroJim** » 22 Mar 2008, 20:37

If it starts easily with one burn of the glowplugs then they're really healthy.

Your rough running is all down to air getting into the fuel lines. The Bosch pump is especially sensitive to air.

The favourite areas for leaks are leakoff pipes (the small pipes daisy-chained between injectors and going back to the pump), the fuel filter housing drawing air, the priming bulb being perished and a small leak anywhere else on the fuel lines.

The fuel lines, priming bulb or fuel filter will never leak diesel as they are all under suction but they will draw air.

A useful diagnostic aid is to replace the section of fuel line between the filter and pump with a transparant lenght. You'll then be able to see any air.

Replace your leakoff pipes. There is a good chance this will fix it.

This is a very common problem. There are loads of posts on it lurking around this forum.

coopertron · Unread post by **coopertron** » 22 Mar 2008, 20:57

Thank you for that info Jim - I was hoping it wasnn't something like that...

Thinking about it, this might have started happening a little while after a tried to drain the "water" out of the fuel filter. The light has been flashing on and off quite merrily for some time. I drained some fuel out, but couldn't see any water in there.

Could this have allowed some air in the system do you think?

Here is perhaps a silly question - can I get the leak off pipes from any motor factors, or does it have to be Citroen. Is there any particular type I should go for?

Thanks again

admiral51 · Unread post by **admiral51** » 22 Mar 2008, 21:08

i think you can get them from most motor factors i got mine from the local diesel specialist cost me under a fiver including the blank.

i had cause to "borrow" the fuel filter drain off pipe today and when i undid the screw fully it ran a bit lumpy and then died
worth a look at the drain screw in case its not fully refitted

colin

Unread post by **CitroJim** » 22 Mar 2008, 21:30

Any good factors, including Halfords, will have leakoff pipes. Some are better than others. Ensure what you get is a good, tight fit on the injector spigots; I've seen some pipe that is a rather loose fit and this is worse than useless as it'll still draw air. Also, ensure you get the little blanking plug for the last injector spigot!

You must have an early Xantia if you have a water in diesel lamp. The sensor was deleted in later models and a good job too! It cries wolf something terrible. It really is way too sensitive and drives me bonkers in my old 1.9TD. I drive my 2.1TD in sweet oblivion of any water in the diesel

The housing could draw air from the drain cock if it does not seal well. Another favourite place is the white end of the fuel heater thermostat that can be seen down low and to the right (as you look at it) of the filter housing.

coopertron · Unread post by **coopertron** » 22 Mar 2008, 21:44

Thanks again for the advice Jim and Admiral.

I presume if it is the pipes, that this will be ok from GSF:

N18600 DIESEL LEAK OFF PIPE ALL DIESELS/TDS RETURN BETWEEN INJECTORS 3.50 each

Can't see a mention of the blank though.

Will this harm the pump at all, and will the car be using a lot of diesel up initially when it starts?

I am tempted to plod on until the weather clears up a bit for more tinkering.

Unread post by **CitroJim** » 22 Mar 2008, 22:04

It is very likely the GSF kit will include the blank. I'd be surprised if it did not.

coopertron wrote:Will this harm the pump at all, and will the car be using a lot of diesel up initially when it starts?

No, not at all. Basically, the rough running is the result of the pump filling up and bleeding itself of air. The more damage, perhaps, although very small, is being done to the engine mountings and exhaust manifold joint as the engine rocks.

I find it helps to open the throttle a little as soon as the engine fires to run it at a fast idle of around 1100rpm until it settles.

admiral51 · Unread post by **admiral51** » 23 Mar 2008, 00:21

that is the correct part number from GSF but............

coopertron wrote:
I presume if it is the pipes, that this will be ok from GSF:

N18600 DIESEL LEAK OFF PIPE ALL DIESELS/TDS RETURN BETWEEN INJECTORS 3.50 each

if that is the price for each pipe then i think that is very pricey

if memory serves me well i bought approx 1 metre of pipe and 1 blank for under £5 so best to ask the question before you spend your hard earned pennies as i have some left over from my purchase of 1 metre

colin

coopertron · Unread post by **coopertron** » 30 Mar 2008, 21:18

Hello again everyone,

I'm not sure if this is relevant to the problem, but I had a look over the cables today, and there are no obvious leaks that I can see, but then I guess it might well be a little pin prick that I wont be able to see...

Also I did notice one quite clearly split cable (which appears to be going to the turbo) there is a pic of here:

Also the only cable I can see going from the filter housing to the back of the diesel pump is the braided type one that goes onto a metal one:

Can anyone clarify what impact the split pipe in the first pic might have, and if the braided cable in pic 2 is the one to replace with clear pipe?

Thanks again lads for your help so far.

Unread post by **CitroJim** » 30 Mar 2008, 21:40

The pipe in the first picture is the pipe that allows the pump to "sense" the level of turbo boost and adjust the fuelling as required. It'll have no effect on starting or cold idle roughness. It will, however, cause the car not to come on boost properly and make it feel a bit flat and lacking in urge.

The braided hose in the second picture is the one to replace with a clear section, if only for test purposes, to see if you have any air in the system.

leakoff pipes can be deceptive. They can look (and feel) fine but still be porus and leaky.

citronut · Unread post by **citronut** » 30 Mar 2008, 21:50

have you tried your local LSUK (lucas) branch for the leak off pipe kit, that is if you have one near you, when i have bought it from my local LSUK it comes in a blister pack with two end caps, for not a lot of dosh
regards malcolm

XantiaMan · Unread post by **XantiaMan** » 30 Mar 2008, 21:58

The boost sensing pipe split will cause a noticeable drop in 'go', replace it and feel the difference!

coopertron · Unread post by **coopertron** » 30 Mar 2008, 22:05

Thanks for the replies everyone.

I thought that would be the case with the split pipe. I thought the car was pretty fast as it is, so I would like to see the difference with the new pipe!.

I presume this wouldn't be much from Citroen themselves? or will any old pipe do from a motor factors?.

Citronut - thanks for the advice re LSUK - there is actually one in Sheffield that I never knew about, so I'll probably pay them a visit.

jeremy · Unread post by **jeremy** » 30 Mar 2008, 22:23

You can probably cut the end off the boost pressure sensing pipe and re-fit it. There is nothing magic about the pipe - anything that is reasonably strong and oil proof will do BUT this one turns through a right angle and so whatever you fit must not kink on the bend.

XantiaMan · Unread post by **XantiaMan** » 30 Mar 2008, 22:53

I just used a spare bit of petrol pipe hose for mine. I cut my old hose originally but after a couple of months it split again, as the heat and age had hardened it, this time it split off completely because it was a little too short.