yes; for some time now (years even?) theres been a smallish rush of air when fuel cap released - in or out, not sure..
why?
fuel cap has no vent hole and vent pipe from tank rear top to filler neck can only work when cap removed, filling up, right?
in the haynes manual it shows another pipe which it also calls a vent pipe - the purpose of which to me is unclear - it connects front of tank upper to the sender/pipe junctions complex on tank top - but why? and i dont see it can be anything to do with the pressurised tank issue either.
just one more thing.. (citing Columbo my favourite tv detective 1968-2003)
on the bulk head after the lower down fuel feed in-line filter there is what looks like another filter (cant be a filter?) but with three pipe connections; in, out and return to tank. this sealed all metal device does not feature in the haynes manual 1988-91, which shows the fuel return pipe coming straight from the weber carburettor.
so what is this device? and why the (unrelated?) fuel tank pressure?
see also my recent thread https://www.fiatforum.com/threads/w...rich-1990-tipo-1-4-running-very-rough.517669/
which may relate to the above two puzzlings. that thread eventually went off in a different direction, involving lawn mowers.. (and came to a halt before and after my last post there) but there were some interesting points made, including possible float chamber over filling and E10 vs. E5 petrol.
beloved tipo awaits my attention with carb dismantle clean out and fit new parts from kit being fav next move. but first id like to get a better understanding of the whole fuel system in case carb is not the source of the problem, hence this post.
kindly thanks folks
just one more thing.. no no thats it
why?
fuel cap has no vent hole and vent pipe from tank rear top to filler neck can only work when cap removed, filling up, right?
in the haynes manual it shows another pipe which it also calls a vent pipe - the purpose of which to me is unclear - it connects front of tank upper to the sender/pipe junctions complex on tank top - but why? and i dont see it can be anything to do with the pressurised tank issue either.
just one more thing.. (citing Columbo my favourite tv detective 1968-2003)
on the bulk head after the lower down fuel feed in-line filter there is what looks like another filter (cant be a filter?) but with three pipe connections; in, out and return to tank. this sealed all metal device does not feature in the haynes manual 1988-91, which shows the fuel return pipe coming straight from the weber carburettor.so what is this device? and why the (unrelated?) fuel tank pressure?
see also my recent thread https://www.fiatforum.com/threads/w...rich-1990-tipo-1-4-running-very-rough.517669/
which may relate to the above two puzzlings. that thread eventually went off in a different direction, involving lawn mowers.. (and came to a halt before and after my last post there) but there were some interesting points made, including possible float chamber over filling and E10 vs. E5 petrol.
beloved tipo awaits my attention with carb dismantle clean out and fit new parts from kit being fav next move. but first id like to get a better understanding of the whole fuel system in case carb is not the source of the problem, hence this post.
kindly thanks folks
just one more thing.. no no thats it
