Lancia Motor Club

Model Technical and Interest => Fulvia => Topic started by: Scott on 15 September, 2010, 11:49:06 AM

Title: Fuel leak ... or not
Post by: Scott on 15 September, 2010, 11:49:06 AM
Bit of a weird problem this morning which I'd be grateful for advice on.
Haven't used the Fulvia for a while but went to start it today to take it to the MOT station.
With the engine running I walk round the front of the car to make sure the bonnet is closed and there's loads of fluid on the ground.
Open the bonnet and it's spewing Shell's finest unleaded on the ground.
No fuel in carb tray but plenty gathering in engine casing nooks and crannies near fuel pump ... asume it must be from the fuel pump via some kind of leak.
Take off air filter housing to get a better look in that area. Mop up all the neat fuel that's gathered in the nooks and crannies. Restart engine to see if I can see where fuel is leaking from.
Nothing. Engine running fine. No fuel leaking.
Not only did I miss my MOT appointment ( :-\ ) but I'm now concerned I have some issue ready to repeat itself at random in the future. And neat fuel in the engine bay is not clever.
Anyone have any ideas?

Title: Re: Fuel leak ... or not
Post by: lancialulu on 16 September, 2010, 11:41:10 AM
S2/3 have fuel return pipe. Mine cracked (old plastic type) and did same as your car. Puddle to the rhs of engine bay (looking fwd).

Quiet worrying.

It may have closed up as not at hi pressure. Worth checking if you have this series.


Title: Re: Fuel leak ... or not
Post by: Scott on 16 September, 2010, 04:10:12 PM
Hi Tim

Thank you very much for your reply.

Mine is indeed an S2 and the puddle is where you explained ... essentially in the vicinity of the fuel pump below the air box.
Now I have something to go on I'll be checking that fuel return pipe out at the weekend!
I'm assuming that if it is knackered then the piping is something generic enough that can be picked up at a motor factors?

Thanks again,
Scott.  :)

Title: Re: Fuel leak ... or not
Post by: lancialulu on 16 September, 2010, 09:17:44 PM
To keep as std I would recomend you buy replacement from Omicron as not expensive... Beauty is that you can see fuel returning...


Title: Re: Fuel leak ... or not
Post by: roddy on 16 September, 2010, 10:21:44 PM
Hello Scott

Word would have it that modern fuels can cause damage and failure to rubber, so replacing flexible piping with the o/e spec Cavis is perhaps a good idea.   I wonder if your leaking/spraying petrol could have been caused by the internal flow valves in the fuel pump being 'stuck'.   The 'bio' aspect of many current fuels, and certainly Shell, is methanol which is hygroscopic and draws moisture from the atmosphere and the vented fuel tank.   When petrol evaporates off, it leaves all sorts of nasties which gum up the works.   The return of petrol into the system will have washed everything sufficiently clean to allow some movement to return, and life appears back to normal?

Regards - Roddy


Title: Re: Fuel leak ... or not
Post by: Scott on 17 September, 2010, 08:29:20 AM
Tim / Roddy - really appreciate the replies. Thank you.

Roddy - what you're saying would make sense. Work commitments means I haven't used my Fulvia for some time and the 'gumming up' hypothesis would explain why fuel seems to be spraying from somewhere (presumably as a result of the fuel being pressurised when it couldn't flow normally); and this gumming being freed up after a while. That would explain why on restarting the engine everything was back to normal.

Tim - I'm onto Omicron now for the piping!
I can't be sure - as my first reaction was to switch the engine off pronto when I saw fuel leaking - but the fuel looked to be coming from around the fuel pump gasket area. However that might just be where fuel was being sprayed. I might get a gasket replacement as well to be on the safe side though.