Baffling engine problem

[billdavies]

If you are thinking the fuel filter is blocking then disconnect the line and extend it through the filler pipe, you could add an inline filter.
Then run the engine the standard Citroen pump should be able to draw fuel forward.
This would be a test set up to prove if the filter is chocked.
If this proves the point then strip the filter out and throw it away, then re-plumb using an inline unit it can be swapped if necessary by only choking the pipe and pulling off, I've done this at the roadside with minimum fuel spillage when I had fuel problems.
Current filter been in for four years
Bill

[Vyv Cox]

Thanks Bill. My problem is that I cannot withdraw the sender unit from the tank because the access hole in the car is too small to allow the unit to be fully rotated. The filter on the end of the pipe is perfectly clean but, as suggested, seems to rise to block the pipe under acceleration. I have tried to push it off the end but there is some restriction to this: I assume an expanded end on the pipe.
Provided I do not accelerate hard the filter is currently behaving itself. I will do something more permanent when we return home.

[billp]

Maybe a daft question Vyv, but have you got a pressure regulator in the fuel line? There are some cheap ones on the market and they do cause problems such as you state.
Cheers
Bill

[Vyv Cox]

After months of trying different solutions, today I finally found the source of our troubles. Having driven something like 1000 miles trouble-free, including the 10,000 ft event last September, the car suddenly cut out last week when descending from around 600 metres in Spain. As previously I waggled all the connectors, although I suspected a fuel problem. 5 minutes later the engine started fine but cut out again after a couple of minutes. This time we just sat and waited, the engine then restarted and we drove 20 miles back to our base.

Today we headed out of Benicassim into the hills. A mile gone and the engine cut out. After waiting a few minutes it restarted but running very poorly, fortunately enough to get us to a large car park where we could work undisturbed. First move was to disconnect the fuel hose from the carburettor and turn over on starter motor. Plenty of fuel, ruling out any pump or upstream problems. Next I removed the filter in the carburettor, slightly fouled but OK after cleaning and blowing through. Again, engine started but very poor running.

I then took the top off the carburettor, to find almost no fuel inside. I suspected the float needle, although this was new. No obvious problem with it. However, looking inside its housing I could see something black at the base of the threads. I managed to hook it out with a small screwdriver and found a flake of rubber just big enough to cover the hole in the top of the float needle jet.


I have no explanation for this and assume it must have been there before we bought the car. I then flushed the housing through by turning over on the starter motor, replaced the needle, put the top back on the carburettor and the engine restarted full of vigour. We drove 70 miles afterwards and hopefully all our intermittent problems are behind us.

[billdavies]

viv,
I'd revisit the carb re icing.
In the past I had a similar problem in the winter, solved by wrapping the carb with a cardboard shroud. I was stuck in Safeways carpark and it was readily available in the skip.
If the carb is icing when running, the engine stops and by the time you get out mutter a few sweaty words to the Gods, low and behold the ice has melted and there is no problem to solve. The engine starts ok.
Then further down the road the same thing engine stops etc etc.
Give it a try, I may be wrong but it won't be the first time.
Bill

[Vyv Cox]

Hi Bill,

See the post above, problem solved we think.

I can pretty much rule out icing, we are in Spain and yesterday was a pleasantly warm day. On several.occasions in the past and yesterday the engine cut out within less than 5 minutes' running.

[QFAD]

Hi Vyv,

Glad you got to the bottom of the niggly problem!

We had weird electrical fault blowing fuses - after a load of breakdowns and hassles eventually found out is was the bulb inside the amp meter. It had come loose from it's holder and shorted out inside the gauge!! Not doing any night time journeys I did spot spot it was not working!

Enjoy the sunshine in Spain! Lin and I have had many trips on our Guzzi's all over that wonderful country- beautiful empty roads most of the time..