Xantia 1.9TD fuel blockage ?

[Mandrake]

Hi All,

I just noticed on my mums 1993 1.9TD Xantia that the fuel priming bulb is partially collapsed (as if its been squeezed) both while the engine is running and while its not. The car is still running fine at the moment, although I am seldom it's driver so my mums idea of running fine and mine may be two different things

It almost looks as if there is a blockage somewhere between the fuel tank and the primer bulb, and the pump is sucking hard - has anyone else had this collapsed primer bulb effect before ?

Is there a lift pump in the tank or is it purely suction from the engine end ? Is there another fuel line filter near the the tank end of the fuel line ?

The car usually runs on biodiesel, but is sometimes topped up with a small percentage of vegetable oil, and the engine itself always runs like clockwork.

Regards,
Simon

[DickieG]

Hi Simon,

A good place to start is to pull out the fuel gauge sender unit assembly in the tank (under the O/S/R seat base) as the car may be suffering a build up of sludge on the fuel pick up gauze filter. I believe using veg oil can disturb sludge debris from the tank, this filter will then be the first obstruction it encounters.

[deian]

I think it works purely by suction from the engine pump and then return to the tank and so on, with just the gauze in the tank, which as dickieg said could be caked with sludge.

a collapsed priming bulb would suggest a bloackage of course

[CitroJim]

Absolutely in agreement with Richard and Dei on this one Simon.

You need to act fast as the blockage and increased pressure it cauuses can burst pump seals and burst the fuel filter, especially down by the fuel heater thermostat seal, the white projection at the bottom of the filter housing.

A quick and dirty (temporary) clear job can often be done by applying an air-line to the fuel return line at the pump end. If all is clear on the return line you should be able to blow down the line and make bubbles in the tank!

[lexi]

Biodiesel mixed with dinodiesel is fine but do not mix BD with veg oil.If you cannot clear it mechanically then put some dino in it...........you know that expensive stuff that causes much wailing and gnashing of teeth Couple of teaspoonfulls of Isopropyl might shift it. Then gather it at your filter. Hopefully you have fitted one before the main unit.

It will be working ok at the engine because of the heated element but will still be cold in the tank ......contributing to sludge. I have noticed that the plastic tank does not seem to hold as much old diesel filth as the steel ones I have had.

[AndersDK]

To moake it clear : the D/TD's dont have lift pumps like the later HDI's or the petrols.

[Mandrake]

Thanks all, will look into it.

Regards,
Simon