xantia TD one time fail to start

[aerodynamica]

Oh yes, only other trend might be that the tank is less than 1/4 full today - it's just this side of bringing the light on.

[Xaccers]

6-7 squeezes suggests an air leak between the primer and the pump so check all the joints

[aerodynamica]

Will do but how is the entire diesel pump emptying?

[Xaccers]

Will do but how is the entire diesel pump emptying?

The leak off pipes have a return to the pump, so if air can get in it allows the diesel to flow back to the tank

[Xantidote]

I have to agree with Xac - 6/7squeezes of the bulb seems a bit excessive. You say you've replaced the bulb - is it similar size to the original?

Very odd that it's run for 3 weeks since the problem first came to light. Any air leakage in the pipework would allow fuel to leak back to the tank, but the fuel would be slower running back to the tank if the tank were full rather than empty. May be worth watching to see if fault only occurs when tank fuel level is low. This approach wouldn't pinpoint the exact location of the air leak, but would identify if an air leak is the actual problem.

You've replaced the original fuel filter with an in-line one. If it has a clear casing, see if you can see any fuel/bubbles when it's next difficult to start. The fuel line will be smallish diameter, and I've found it can be difficult getting small size hose circlips to give a good seal.

Had you done any work on the fuel system in recent times, just before the problem first came to light? Not recently had reason to access the in-tank fuel gauge mechanism, or disturb the fuel lines from the top of the tank?

[aerodynamica]

Hiya, I took the fuel tank sender out way back 2 years ago to check the filter. The car started instantly after work there and again in Tesco Car park.

As for the replacement bulb, it's the same size and same size of pipe inner diameter fittings.

It's a mystery given the number of replaced items that were not recent

[aerodynamica]

Will see what it does tomorrow!

[Xantidote]

I'm sure you'll get to the bottom of it. At least it always starts for you, in the end

[aerodynamica]

Cheers and this morning it started on the button - tipped up diesel to half tank

[aerodynamica]

Arg it's back!

3/4 full tank but tis morning it was up to its old tricks. Primingg bulb needed a good 20 squeezes but did start. I would say the priming bulb never went hard at all- I am sure the diesel could be seen foaming in the clear filter to but it was dark. Has to be an air leak but I feel it's somewhere between the bulb and the tank as opposed to bulb and filter or diesel pump

[Xantidote]

After your last post, I was going to say "see you again in 3 weeks", but it's not even been that long. With your saying there was not much pressure at the bulb, think we've tracked it down to air in the fuel line, which at least is something.

Some of the fuel line will be the original, and I know from experience earlier this year when I had a split in the rubber hose, that the original rubber hose is now becoming less flexible and bendy on cars of our vintage. Still OK until it's disturbed. Maybe you have distorted/bent a bit of the old hose when doing your previous repairs - for example, there's a 90 degree bend where the line comes up the bulkhead, and it turns sharply to connect to the pressure bulb, which you replaced 2 years ago.

It could also be at a joint - I've found it difficult in the past getting a good seal on a small diameter hose, particularly if using a jubilee type clip.

In the old days of BXs, they sometimes suffered air in fuel, particularly if parked facing up-hill. I read somewhere that one way to track down a leaky joint was to smother the joints in grease, but never tried this myself.

If the leak were really bad, and it's on fuel pump/engine side of the pressure bulb, then I'd try squeezing the bulb to build the pressure and look for fuel actually leaking from the fuel line as you pressurise it.

In the back of my mind is something I read on the Forum about a 1-way valve somewhere (maybe in the pump?). Not sure if this is applicable to your model - can't remember the context/engine/fuel pump type - maybe someone else can help with this?

[aerodynamica]

Cheers Martin I found the original leak in the filter Housing that same way. The length of pipe from the track sender to the bulb it's original ask quite likely candidate

[uncle buck]

The priming bulb has a one way valve in it.

I know you replaced the leak off pipes a year or so ago but it might be worth reseating them by cutting a little off the end of each one so they have a new grip onto the nozzle they connect to.

[aerodynamica]

Good idea will do. I've just been out to the car at lunch break and the fuel filter was full of fuel and the bulb already hard ( i.e. Took one squeeze) it started instantly say one turn of the starter. Intermittent air leak?

[uncle buck]

It certainly displays all the characteristics of an air leak.

Air leaks of this nature can be hard to track down, so it's best not to overlook anything. The only way to find them is to systematically work your way through the whole system one thing at a time so you know when you have cured the problem, this can be hard and time consuming with an intermittent problem.

Leak off pipes are always a suspect as they are fixed to the injectors which get quite hot so the pipe ends can become brittle.



Cheers.