Technical uno cutting out

[earthmoverpdt]

I have a 1997 Punto 1100 petrol When cold and warm it runs like a dream but when it gets hot it cuts out at the lights etc i have been told O 2 sensor on carb is duff and its dear to replace any suggestions ?

phil

 

[earthmoverpdt]

Re: punto cutting out

I have a 1997 Punto 1100 petrol When cold and warm it runs like a dream but when it gets hot it cuts out at the lights etc i have been told O 2 sensor on carb is duff and its dear to replace any suggestions ?

phil

i mean its a UNO sorry for confusion its
only got 37 k so worth fixing if any one can suggest possible problem much appriciated :slayer: :yum:

 

[alexGS]

Re: punto cutting out

OK, Hello - welcome to the Uno Forum

O2 sensor on carb... I think that's way off... Firstly because if it has an O2 sensor (in the exhaust) then it's fuel-injected (no carb). Sorry I'm not trying to shoot you down, just trying to narrow the possibilities

If it is fuel-injected, then yes it may be the O2 sensor. And, I think being a later Uno, it will be fuel-injected - but hang on, a 1997 Uno? They stopped making them when the Punto came along in '94.

There are lots and lots of possible answers to your question...

A common favourite for running difficulties like you describe (cutting out when hot) is the finned ignition module on the distributor, but really we need a little more info. Is it just that the engine won't idle - can you keep it running with the accelerator?

If it's fuel-injected, there's a switch on the throttle body near the accelerator cable attachment (first pointed out by Monty Mort, a member who has now moved on to a Stilo and still fixes it like an Uno!) This switch needs to click 'closed' with the pedal released, as it reduces the amount of fuel delivered by the injector. I can guess that with the engine cold, the extra fuel would go un-noticed, but with the engine hot, it would severely reduce the idle speed. Basically, it needs an accelerator cable adjustment to rectify, but you could also check the switch with a multimeter.

I picked out one of many causes at random - I think we need more info for a convincing diagnosis. I don't have personal experience of later injected Unos and I hope someone can jump in and correct me where needed

So - are you sure about the year? Injected or carburetted? And what type of cutting out - does the engine restart, does it drive OK when moving, etc.

I just thought of a completely different scenario if it's a 1987 Uno 1116cc - the fuel cutoff valve on the carburettor - might be cutting off - but it wouldn't be the valve at fault, it would be the control unit that drives it! You can wire the valve to the ignition coil orange wire so that it's on all the time. However, since you're in the UK - I suspect that most 1987 Unos have safely rusted away...

Thanks,
-Alex

 

[Big Howie]

I have a 1994 Uno Start 1.0ie and I have exactly the same problem - itermittently dies with violent hesitation once engine reaches normal operating temperature . New filters, sparks, leads and distributor have not resolved it. Any ideas?

 

[Chas Uno]

Could be the ignition amplifier module on the side of the distributor. When these start to fail they do so when they get hot. If the car is fine until it gets warm then it's a likely culprit.

 

[Uno driver]

hang on, a 1997 Uno? They stopped making them when the Punto came along in '94.

​

Production stopped in October 2002 (Poland)

 

[red1]

Mine's a 97 model bought in Malta, I think they were rated highly and in quite a few countries they continued to be available long after the Punto. Just shows how many people use the forum.

 

[alexGS]

Mine's a 97 model bought in Malta, I think they were rated highly and in quite a few countries they continued to be available long after the Punto. Just shows how many people use the forum.

Ah - but the original poster was in England - and FIAT stopped making the Uno for the English market in 1994, so a '97 Uno wouldn't exist in England. That was what I meant to say, but I didn't quite get it clear Sorry for the confusion! (FIAT Brazil also makes the Uno currently, FIAT South Africa/Nissan made the Uno until 2004 if my memory serves).

Anyway the original poster turned out to be a one-hit wonder, which is a bit of a shame. I reckon it was an '87 1116cc Uno and it was the fuel cutoff control unit that was 'dear to replace'.

We should perhaps consider a sticky of 'common running faults', as these answers (finned module, vacuum advance unit, SPi throttle switch) seem to come up again and again?

-Alex

 

[red1]

Excellent idea, I have been thinking about trying to list the cutting out threads which also appear regualar in another forum I found (espacially in relation to Puntos).

However could you help please by confirming if the Haynes is correct for the following.
Car is UNO 1.0ie Injection.1997 Malta edition. To adjust the accelerator cable Haynes says to use two 10mm shims. Is this correct, 10mm seems a bit hefty when I look at my arrangement??
Thanks.

 

[red1]

Re: punto cutting out

OK, Hello - welcome to the Uno Forum

O2 sensor on carb... I think that's way off... Firstly because if it has an O2 sensor (in the exhaust) then it's fuel-injected (no carb). Sorry I'm not trying to shoot you down, just trying to narrow the possibilities

If it is fuel-injected, then yes it may be the O2 sensor. And, I think being a later Uno, it will be fuel-injected - but hang on, a 1997 Uno? They stopped making them when the Punto came along in '94.

There are lots and lots of possible answers to your question...

A common favourite for running difficulties like you describe (cutting out when hot) is the finned ignition module on the distributor, but really we need a little more info. Is it just that the engine won't idle - can you keep it running with the accelerator?

If it's fuel-injected, there's a switch on the throttle body near the accelerator cable attachment (first pointed out by Monty Mort, a member who has now moved on to a Stilo and still fixes it like an Uno!) This switch needs to click 'closed' with the pedal released, as it reduces the amount of fuel delivered by the injector. I can guess that with the engine cold, the extra fuel would go un-noticed, but with the engine hot, it would severely reduce the idle speed. Basically, it needs an accelerator cable adjustment to rectify, but you could also check the switch with a multimeter.

I picked out one of many causes at random - I think we need more info for a convincing diagnosis. I don't have personal experience of later injected Unos and I hope someone can jump in and correct me where needed

So - are you sure about the year? Injected or carburetted? And what type of cutting out - does the engine restart, does it drive OK when moving, etc.

I just thought of a completely different scenario if it's a 1987 Uno 1116cc - the fuel cutoff valve on the carburettor - might be cutting off - but it wouldn't be the valve at fault, it would be the control unit that drives it! You can wire the valve to the ignition coil orange wire so that it's on all the time. However, since you're in the UK - I suspect that most 1987 Unos have safely rusted away...

Thanks,
-Alex

Alex what do you mean by a "switch" is it the idle plunger?
thanks

 

[Ucof]

Ah - but the original poster was in England - and FIAT stopped making the Uno for the English market in 1994, so a '97 Uno wouldn't exist in England. That was what I meant to say, but I didn't quite get it clear Sorry for the confusion! (FIAT Brazil also makes the Uno currently, FIAT South Africa/Nissan made the Uno until 2004 if my memory serves).

alexGS, I bow down to your almighty knowledge!!! :worship:

Have you thought about a girlfriend?