Fuel blockage?

[Scott]

Out of character but I left my Fulvia run very low on fuel. It could be complete coincidence but she is not now running as smoothly as she should. The symptoms are that there is a struggle to go above certain revs. Could there by some kind of blockage e.g. as a result of possibly sucking 'sludge' from the tank by letting the fuel run so low?

The inline filter at the carb end is looking okay - and to be on the safe side I have changed it - but is there a filter at the tank end I need to be aware of. Where is it and can I replace/clean it?!

Also ... if I look in the boot and trace a line from the top of the tank there is a plastic thing mounted on the inside wheel arch. If I tap it, it is hollow. What purpose does this serve? Never really paid it much attention before but I'd like to know. Assume it is some kind of breather mechansism ()

I may be jumping to the wrong conclusion with the fuel and it might be something else completely different so if there are any other suggestions for me to look at I am grateful for any info. Has anyone had bad experiences with electronic ignition (Lumenition) for instance. The reason I mention this is that a while back my car had a funny turn where it was jumping and stuttering but, after leaving it turned off for a while, was then okay and has not repeated this incident. I'm not necessarily blaming the electronic ignition but this is the only non-standard aspect on the car.

Many thanks.

[ncundy]

Th filter in the tank is part of the fual tank drain plug assembly - if you remove that you will see it (there is a picture of one here http://www.lancia.myzen.co.uk/forum/index.php?topic=78.60 without the gause filter around it). It can be cleaned in parafin or similar.
The box you mention is a vapor and overflow trap. If any dirt is in the fuel line it may also be in the carbs - although if your in-line filter is and hasn't been dirty then maybe not that likely

[Scott]

Hi

Appreciate the speedy reply.
Assuming I can get the petrol out of the tank without too much issue ( ) then is this a relatively straightforward job?
I've navigated to the picture you mention (many thanks) but it's not clear how the filter integrates - I obviously assume the fuel feed line must go via this somehow (i.e. the fuel line must be attached to this plug) but it's not easy to see how. I'm not going to have some horrendous "oops it's popped off" issue as I ease the drain plug out am I 

[inthedark]

As you unscrew the drain plug you will find the gauze filter held in place by the two legs of
the drain plug,  the filter simply slips over the pick up pipe,

That's about it really.

Geoff

[ncundy]

A before and after to add to Geoffs words. The feed just sits inside the filter and the return runs down the outside (about 1/2" away on mine). If the gause has detached or rusted away, you may find that when you try to remove the plug the legs try to wrap themselves around the feed and return pipes (thats why mine are bent in the first photo). You just have to be gentle and do it by feel (she said !!).

The gause on mine had long since gone, so I made up a new one and soldered it in place.

[Scott]

Brilliant stuff.
Really appreciate the replies from yourself and Geoff. That makes it a lot clearer - this being an area of the car I've never investigated. before!
Just one last question ... 
I note your gauze was kaput and you made a new one. Where did you obtain this kind of fine mesh gauze from?
This is sounding like an achievable Saturday morning job (assuming it's not hacking down with rain!)

[St Volumex]

I had to do the same on my wife's Fulvia when we bought it after it had stood for 7 to 8 years.  We also removed two teacups of rust flakes from the tank over the next few days as well!

We put the drain plug back without the mesh which had rusted away, and added an in-line disposable plastic filter which we've also relaced a few times as the tank is getting cleaner.  What I'd really like to do is add a Filter King unit, as it seems the bulkhead on the RHS comes with tapped mounting holes already ?  (Has anyone done this, and knows which Filter King model fits?)

Back to the mesh:  Just this Saturday I received a piece of very fine stainless steel expanded metal wire mesh which will be ideal for the job, and which I plan to silver solder onto the brass drain plug.

Kindest regards,

[Neil]

I fitted a Filter King pressure regulator/filter to my S2 1300 coupe, when I fitted Dellortos, see picture, below, fitted on the inside wing near where the supply pipes emerge from under the car, I did block off the return pipe, the smaller of the two metal pipes, as it been recommended by the carb suppliers, not sure if this was a good move and retained the mechanical petrol pump, any thoughts here?  I have replaced the filter gauze in the tank recently for when it returns to the road, hopefully soon!

[lancialulu]

Another tip re fuel tank filter (which btw could be a wrestle to undo...) is that I found some inline replaceable nylon filters more or less exactly correct dimensions at local motor bitsa shop (the ones that go in upmarket in-line glass fuel filters) and used that.

If your filter has disintegrated then problem could be with rubbish pulled through to the fuel pump. I have once had (not on a Lancia!) the mechanical fuel pump almost stop because of the rubbish impleading the diaphram - interestingly the valving still worked.

Tim

[Scott]

On that subject ... I've just been looking at the Demon Tweeks web site for a possible filter solution. They do a nice in-tank filter for £112.50, but unless it's filtering out gold from my super unleaded to justify its price, that's a no (of course I jest as I could never get this into the tank!). An alternative, however, appears to be a pick up filter for in a tank at a more reasonable £12.50. This might offer a more immediate solution but they cite '-6 or -8 hose' sizes. Does anyone know what pipe size is in a Fulvia tank in case I take this option?

Tim made my heart skip a beat ... but of course the Fulvia has an inline filter so I hope the chances of getting a bit of crud into the fuel pump that would cause it to go so wrong is slim. Also, in my case, I have a separate electric fuel pump hooked up. This was installed following a nice little article in Viva Lancia (by Andrea Nistri I think) a while back recommending this approach to save wear and tear when the car has not been started for a while. Basically the pump is just fitted in line with the existing system and is used to prime the carb by running it prior to attempting to start the car - rather than churning the engine over and relying on the mechanical fuel pump. This system works really well and even if I haven't used the car for a while it will fire first time after such a prime. Anyway, I digress, my point is that when I've got to the situation where my car is 'stuggling' I've pressed the button on my dash that runs the electric fuel pump but the reluctance to go is still there so I don't believe this is a pump issue. Assuming it is a fuel starvation issue then my thoughts are either it's because I have a blockage at the tank end - and am therefore simply not getting the fuel quantity through - or unfortunately something's bypassed the inline filter and is causing issues with the carb.

If my weekend tank filter doesn't work can everyone look out for a posting next week ... "How do I diagnose and fix a blocked carb"!!! 

[ncundy]

I can't remember where I got the gauze from - I just had some. I had a quick look on google and there seemed to be a few places selling it, have a quick search and I am sure you will find someone local. The pick-up filter is an attractive option, but I am not sure how you will be able to fit it to the feed pipe ? The feed pipe in the tank is 8mm OD on mine.

[Philm]

When people quote 'dash' sizes they are talking in 1/16" increments so a -2 hose is 2/16" bore or 1/8" -8 is 1/2" and so forth. It also applies to aerospace fasteners. Dash sizes are most commonly used in motorsport or aerospace.

[inthedark]

One other thing to check is - breather. run the engine up and then remove the filler cap, if it goes
wooosh it may be a blocked breather. Also be sure to blow back down the fuel line to ensure the
pipe is clear. I seem to remember on mine there was a rubber "O" ring sealing the filter to the pick
up pipe, over time it had degenerated (bit like me) and bits had gone up the fuel pipe.

Geoff

[Jai Sharma]

By the way, you can/could get the gauze bit ready made from Omicron, when I bought one it was less than £5 if i remember (maybe even £2??).
And the tank drain plug takes the same tool as the sump plug. It can be hard to undo but is brass if I recall so hopefully won't be rusted shut.
I had problems with a lumenition kit once, the car would cut out when warm, then as it cooled would be fine. It was the "box" of electronics. An easy fix but a complete pain to live through!
Jai

[Scott]

Many thanks for all the advice and replies. I'm very grateful for your various inputs as this will ensure I cover all angles when I do this job at the weekend.

Jai's comment is interesting as, from my original posting, this is an area of suspicion - although the car runs absolutely fine at lower revs it's only when 'pushing on' does the reluctance to go and stuttering occur. Would an electronic ignition system produce this kind of problem?