Technical The worst economy from a uno ever

[smit.coert]

Situation critical reached with my uno sx. I had to remove the injection system and fit a carb, as my ecu had a misunderstanding with the positive terminal on the car bat. The car is fitted with a 32 weber now, it's running about as good as i can make an old weber run, but it's stil rocket science to drive the thing.. But beside's the point.. The big problem is it's economy.. How does half a tank of petrol sound for a 27km trip? Nasty i tell you nasty.. The car smells of petrol on the outside after driving it.. Even if i relax on the gas.. Anyone who know's how to jimmy or fix this problem?

 

[Jai]

you sure you not leaking anywhere? around the tank or along the fuel line?

 

[smit.coert]

Not leaking at all checked everything.. The car can stand for day's and the petrol level stay's the same.. Even try'd keeping the ign on so the pump runs and following the pipe's as far as i can..

 

[alexGS]

I'm sorry but it's just too hard to say what's going wrong here...

Is the float level correct? Are the primary and secondary jets in the right places (cross-check against Haynes manual)? Is the ignition timing correct? What about the fuel pressure - it sounds like you are using the fuel injection pump to run a carburettor? There's just so many variables...

-Alex

 

[smit.coert]

I'm sorry but it's just too hard to say what's going wrong here...

Is the float level correct? Are the primary and secondary jets in the right places (cross-check against Haynes manual)? Is the ignition timing correct? What about the fuel pressure - it sounds like you are using the fuel injection pump to run a carburettor? There's just so many variables...

-Alex

i have changed the pump, servived the carb, changed the filters, checked all the pipes, spent about 50 hours looking at the damb thing, im mearly short of talking to the thing and see if it can talk. next would prob be some tnt in the boot to see if it flys too.... got the injection system and all its parts tho just the ecu is fryed and someone is looking at it as we speak......(I hope at least)

 

[alexGS]

i have changed the pump, servived the carb, changed the filters, checked all the pipes, spent about 50 hours looking at the damb thing, im mearly short of talking to the thing and see if it can talk. next would prob be some tnt in the boot to see if it flys too.... got the injection system and all its parts tho just the ecu is fryed and someone is looking at it as we speak......(I hope at least)

I'm concerned that the fuel pressure (from the pump that you've replaced but that is presumably an injection-type electric pump?) will be too high for the carburettor to shut off (via the floats and needle valve). Therefore the carburettor is flooding - with most of the petrol going straight into the engine (harmful) and also evaporating to give the petrol smell.

What you need to do is either fit a mechanical pump to the engine block (as used on the FIAT Tipo or carburettor Uno), or a low-pressure electric pump in the line (available aftermarket).

OR - and this is the better option - refit your injection equipment which will always be more efficient than the Weber carburettor.

-Alex

 

[Chas Uno]

Hang on, you say it's a Uno SX and you've fitted a Weber 32 to it? The Weber 32 TLF carburettor was fitted to the 999cc and 108cc FIRE engined Unos and the SX only had the 1300/ 1400 Lampredia engine as an option (in the UK). I wonder if you've somehow fitted an unsuitable carburetor for your engine?

The mk2 Uno SX used a throttle body that is very similar to those fitted to the FIRE engined models. The mk1 SX used a twin choke Weber that was only fitted to the 1116cc/ 1301cc inlet manifold. It's possible that you've got totally the wrong carburettor for your car.

Can you tell us what engine capacity your SX is and what car you took the Weber 32 from?

 

[alexGS]

:yeahthat:

I assumed that it must be a 30/32 DMTE, not a 32 TLF.
Otherwise it wouldn't have fitted onto the intake manifold - the only way would be to get the single-choke carb and manifold off a really early (<1985) Uno 55 1116cc.

I once saw a newspaper headline, "Are carbs really bad?" and my immediate response was "Yes, of course they are, fuel injection is the way forward." However, the article was talking about dietary matters. My feeling still holds, though.

-Alex

 

[smit.coert]

it is a 1400 91 model. the pump is from a bush machanic. the weber looks abused no doubt. the jets both say 160 on them is that more or less right?? My ecu is fryed like a potato chip after a night in the oil. im stil trying to ressusatate it. i noticed the elec shut of is missing and the hole pluged with some bolt. the car is also for some od reason running bad.. use to fly but now even smart cars take me out.. thats til 140 thou as they governed til that. cant i seal some of the jets os something??? this car is making me crazy as you can imagine

 

[smit.coert]

oh ya can petrol evapourate out of the flot or spil in some way?? the carb pops when i start cold

 

[thepottleflump]

Bush mechanic, you in SA? You sure you're not leaking from a fuel pipe connection somewhere? If the tank was leaking you might see a drop in fuel, but if the line is leaking probably not. if the car is massively overfueling, it'll run bad, you'll wash the bores and the engine will turn to scrap. You headgasket ok? Sounds like you're in a whole heap of trouble with the car.

 

[alexGS]

Sounds like you're in a whole heap of trouble with the car.

I completely agree - get that carb off, throw away that pump - even though I still don't know if a 'bush mechanic' pump is fuel-injection-pressure (about 30psi) or carburettor pressure (3psi)! We're just not getting any closer to narrowing down the problems with your setup because we're not getting the details. It sounds like you have a 32DMTE but that's still just a guess.

I don't think we're qualified to tune the carburettor when we don't know if the fuel pressure is right, or whether it's flooding because the pressure is too high, or perhaps because the float level is wrong (bend the floats further away from the cover).

The '160' that you see is the air corrector size. Unscrew that and a long perforated brass emulsion tube comes out with it - and pushed into the bottom of THAT is the main jet. There should be two different sizes - the secondary should be the larger. You could try swapping them over, but that's really hit-and-miss if you don't know how the carburettor works. There could be blocked idle/progression jets (the other small 'screws' next to the air correctors).

It would be a lot better to re-unite the long-suffering engine to its fuel injection setup - and get an ECU from a wreckers - there must surely be Unos in wreckers?

Before you fire it up with the new parts, make sure you've earthed all the earth wires (usually black), and make sure there are no shorted wires - check the insulation, especially on the wires to the injectors themselves. The ECU must have become fried for a reason!

-Alex