Technical uno fire 999cc flooding carb

[uno045]

Hi there,

I have a 1984 uno fitted with a fire engine 999cc. Recently the carb weber 32TLF started flooding, but it would do it once and then 2 weeks might pass and it runs with no prob. i've bought a new kit and changed the needle some jets and so on but it still does flood sometimes. I've checked the vacum advance unit but it works fine. I checked with haynes manual and the only diff i can find is that the float travels around 4cm instead of 4cm something as stated. Any ideas?

 

[alexGS]

Hello, welcome to the forum

I thought the FIRE engine began in 1986... but anyway... it really has to be the needle valve or float, doesn't it? Sounds like dirt getting caught in the needle valve. Have you tried installing a fuel filter if you don't already have one? The filter is usually mounted before the fuel pump due to the very short distance between the pump and the carburettor. That does make me wonder about what debris might come from the pump, but there is usually also a mesh screen on the carburettor inlet that you get to by undoing a large brass nut.

The small difference in float travel is unlikely to cause the intermittent flooding in my opinion. The float level must not be too high, of course. Usually if you hold the top of the carburettor sideways, the floats should hang vertically just as they touch the spring-loaded ball on the needle valve. Then the Haynes manual quotes the distance between the carburettor top (incl. gasket) and the short base of the float as 27mm.

Also check that the needle valve seat has not worked loose - it's a small hexagonal nut with a washer, check for cleanliness.

Check that the float definitely moves freely - there might be some little hold-up (bent pivot pin etc.) that is causing it to stick.

Compressed air is useful when you take carburettors apart, as it helps to blow all dirt/dust away.

Cheers,
-Alex

 

[Chas Uno]

I thought the FIRE engine began in 1986...

The FIRE was introduced in 1985. First to the Lancia Y10 and then the Uno 45. As far as I'm aware, only the FIRE engine had the Weber 32TLF carburetor fitted, so I am as confused as Alex as to what model Uno you have!

Mind you, a 1984 Uno! One of the oldest still around, and could rival Alex's friend's 1984 70S for oldest Uno still running. What's the latest on the 70S Alex?

Have to agree with everything Alex says. An intermittent flooding carb is almost certainly a sticking needle valve or float (the float operates the needle valve) caused by dirt or ridges on the needle valve and/ or where it goes into the jet.

You can still buy a carburetor overhaul kit for the 32TLF and this will come with a brand new needle valve as well as all the necessary gaskets

Do you have any pictures of your Uno?

Chas

 

[uno045]

Hi there,

Many thanks for your reply. First my uno is a 1984 (45) model mk1 which originaly had a 903cc engine. 3 years ago I fitted a fire engine & a 5 speed transmission which was brought from italy.

I took the carb out again, unscrewed the whole body of the needle valve but found no dirt. Now i just bent a bit downwards the the part on the float that touches the needle valve. The car seems working properly as i did around 50km with no prob for now!!!!

Also I do have a fuel filter installed before the fuel pump, but this carb does not have the scrweable plug at the side where to fit the small filter.

 

[uno045]

Hi,

My uno is a 1984 model originally fitted with a 903cc engine. The FIRE 999c engine was fitted 3 years ago.

As i already told our friend alex I have already bought the carb kit and fitted the new needle valve. There is no dirt trapped neighter on the needle itself neighter inside. I now just bent a little bit downwards the float part that operates the needle and did 50k okay.!

regards
elton

 

[Fegco]

Hi,
i've got a 60sx uno (1108- F.I.R.E.), in the past i have the same problem that you do, and it's easy to solve.
The 32 tlf Weber carb, got a power valve(a little membrane with 3screws), when you remove the filter, it is above the electric anti-Flood Valve, what is needed to do?!? easy
Take it out, clean it, and most of all, see the spring, that spring is very important, got to be with original mecanics quality (Tension, Size,Rust-free). If Possible use a borought carb to compare.
When i Bought the Weber repair kit, (that came in a bag) the same thing as appened to me, so by comparison(sorry my english) i was abble to put it near to factory default.
That valve (power-valve), by the air vacumm created in the venturi, put the correct amount of fuel to be burn, and variates by not only by throtle, but also by RPM charge.(it's a machanical way of doing what ECU's do, but with no comparison, of couse.



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