Fuel System Bleed Off

kagey · Post by **kagey** » 20 Jul 2007, 12:27

Howdy folks, long time lurker, first time poster !!!

You guys supplied me with all the information required to change my spheres job done clean as a whistle in 20 mins begining to end, much-oh thanky-oh

Right having searched and rustled through my useless Haynes manual, its a first time i've drawn blanks, but with Citroens it does appear to be useless

Like the pauper i am I went and let my Xantia Diesel run dry trying to make that allusive run to the petrol station, and now the car is giving me grief starting it up in the mornings.

My question is this,
I find the best way of starting, is to manually pump some fuel through using the primer bulb (incidentally i can hear a little hiss after doing this for a while)
Now I believe I have to bleed the fuel system totally if having run dry,
the manual shows a picture of a dark bit of the injection pump with something sticking out and says bleed off screw, yet doesn't show it on the diagram of the pump

The car is a 1995 Xantia SX 1.9TD

Supplemental, Its useless climbing hills and accelerating, when its upto speed not a problem
And the glow plugs are about to be changed to see if they help with the starting issue

anyhow any help and advise would great

Post by **CitroJim** » 20 Jul 2007, 12:44

The Bosch on the 1.9TD is self-bleeding so no worries there. A few pumps on the priming bulb and off it'll go and quite happly bleed itself. It is self-bleeding on account of being an "open" pump in that manual pumping with the priming bulb will pump diesel straight through the pump and down the return line even with the stop solenoid de-energised.

The Lucas pump is too but only with the ignition on and the stop solenoid energised.

When you let a tank run dry you'll pull up all sorts of crud and water into the system. This will all be intercepted by your fuel filter which is likely to be well and truely choked now. I'd change that first.

Glowplugs are a good idea to replace, especially now winter is not that far off but if the above fail to resolve it, you need to look at air leaks on the fuel supply side. The injector leak-off pipes are a favourite and you'll find many Posts referring to these and air-leaks and difficult starting in general.

Generally, if your glowplugs are poor you'll have white smoke from the exhaust whilst cranking. White smoke is unburned fuel which shows fuel is getting through. If no smoke then an air leak is the likely cause.

My money is on air leaks. If you have a transparant fuel supply pipe between the fuel filter and pump (many have) you will be able to see big bubbles if there is an air leak. If you don't have a transparant pipe, a temporary one can be made up to help diagnosis.

kagey · Post by **kagey** » 20 Jul 2007, 17:46

cheers Jim you get 5 gold stars

huzzah, yes we have white smoke
and nope we ain't got no transparent pipe, but yup easily sorted

from the points you've made i'm going to hedge my bets on a combination of glow plug and air leek,
the patient is fine once you've managed to wake her up but her knees seem to give way climbing up the stairs and legging it to catch the bus

by any chance are there any definitive idiots guides to the debacle that I believe glow plug replacement can be and leek-off pipe replacement (what and where are these ? seen these mentioned in turning around a lame donkey into a sprinting stallion)

Post by **philhoward** » 21 Jul 2007, 08:58

For glow plugs i seem to recall a lengthy guide on here recently somewhere, but involves a bent spanner and blu-tack. I've onyl ever done one set (on a ZX TD/Lucas pump) which took me under 30 minutes. I gather that a Bosch pump'd Xant may take up to a couple of hours due to access...

The leak off pipes aren't difficult, just a little time consuming. Getting the old ones off usually involves a pair of pliers as they seem to come off in bits. Make sure you get the end cap for the No.1 injector (I used a Halfords pipe kit which had 2) with any pipe you buy, and don't forget the final link from No.4 injector to the pump.

Another source of air leaks seems to be the fuel filter housing - ususally because something has been overtightened and distorted the plastic housing or pipe stubs - in which case replacement is probably easier. Luckily they seem to be common across all Pugs/Cits so should be easy to find in a scrapyard.

Post by **CitroJim** » 21 Jul 2007, 20:54

kagey wrote:by any chance are there any definitive idiots guides to the debacle that I believe glow plug replacement can be

You need this for glowplugs

http://www.frenchcarforum.co.uk/forum/v ... t=glowplug

It's not that bad really. You do need a good 12mm cranked ring spanner though. It is essential. Blu-Tak is handy, as it a lump of rag stuffed behind the pump to catch nuts and glowplugs that like to fall down there!

kagey · Post by **kagey** » 22 Jul 2007, 11:20

cheers folks

i've made a little list of threads i'm finding useful and commonly asked i'll post the list in order of merit i found workable lol

in the process of changing the leak off pipes any top tips, cause they don't like to be removed do they !!!!

I've decided to cut them round the base to let the air out and break one wall of the tubbing then getting my grips in and making the little fu***rs scream

Post by **philhoward** » 22 Jul 2007, 12:15

Cut the loops in half (to leave stubs), firstly try and pull it off (whilst twisting) so you're not squashing the injector stub. Twisting will hopefully break the initial seal and make them a little easier to remove, but a good pair of pliers are needed - plus gloves for your hands when they let go...