Fiat Uno 1.1 engine stalls at operating temperature

Hi everyone, just recently found this forum and finding it very pleasant and helpful.

I recently bought a 1999 Fiat Uno 1.1 carburetor model. It drove fine for the first 1000 km. Now before I explain what's wrong with it, I want to say that I have read through all the post on this forum that relates to the problem I'm having, but none gave me a definite answer.

The problem I'm having just happened suddenly while driving my car home from town with absolutely no warnings what so ever beforehand, and have persisted eversince.

While driving home my car suddenly just died at a stop sign and would not start. The engine turns over fast but nothing happens. I did however realise that the car sounded like it wants to start when I keep the petrol pedal to the floor while turning the ignition, but then it sounded like a car where the carburetor has flooded.

If I let the car cool down for a couple of minutes it will start right up, until the engine reaches operating temperature - then it just dies again.

I have changed the spark plugs, distributor cap, rotor and fuel filter. I have also let the engine run in the dark to see if there is any arching coming from the ignition wires, and could see nothing.

From what I've read on the forum the problem could be a faulty ECU unit or even the ignition coil.

Any other suggestions as to what the problem may be will be welcomed.

Re: Fiat Uno 1.1 engine stalls at operating temperature

Hi there,

I don't think the carb model has an ECU but might be wrong. Also I didn't know that you could get an Uno from 1999, except if you are in Brazil?
Anyhow, my guess (please note the word guess : is it could be the ignition module. It is that dissipater part attached to the distributor (see this thread: https://www.fiatforum.com/uno/156067-new-ignition-module-also-gets-very-hot.html)

But wait until someone more knowledgeable than me comes along and gives you better guidance.

I hope this helps though for you to have a look at it.

Cheers,
Afonso

Thanks for your reply. I'm from South Africa and Uno's were built here until about 2004. The last batch looking the same as the ones in Brazil.

Your'e correct about the CDI unit on the carburetor, that was what I was deferring to actually, I hear that they tend to go. I can get a new one at a reasonable prize, but the shop is situated in another town 60km away....

MysticEntity said:

Thanks for your reply. I'm from South Africa and Uno's were built here until about 2004. The last batch looking the same as the ones in Brazil.

Your'e correct about the CDI unit on the carburetor, that was what I was deferring to actually, I hear that they tend to go. I can get a new one at a reasonable prize, but the shop is situated in another town 60km away....

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Are you sure it is the ECU as I have same problem with my seicento and am waiting to replace the TDC sensor as on mine looks like this is what is wrong. but more likely to be temp sensor, I changed mine and no change though. I think yours will be TDC sensor it seems a common problem and symtoms are the same. Runs fine cold stalls warm and won't start for 5 mins. When the car runs cold it has rich mix when warm ingnition advances and mixture is leaner this is when yours is failing after cools down injector get a rich mix again but once warm will fail again, Crankshaft sensor common problem. I will verify mine on wed when I change mine

Oh I see !

As it is suggested in the link I sent, check the earthing before you get that module.

Good luck and keep us posted then

moonxx said:

Are you sure it is the ECU as I have same problem with my seicento and am waiting to replace the TDC sensor as on mine looks like this is what is wrong. but more likely to be temp sensor, I changed mine and no change though. I think yours will be TDC sensor it seems a common problem and symtoms are the same. Runs fine cold stalls warm and won't start for 5 mins. When the car runs cold it has rich mix when warm ingnition advances and mixture is leaner this is when yours is failing after cools down injector get a rich mix again but once warm will fail again, Crankshaft sensor common problem. I will verify mine on wed when I change mine

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I stand corrected, but as far as I know only the Digiplex 2 and Microplex ignition systems uses a TDC sensor. My Uno comes with what they call "breakerless ignition", but then again I might be wrong.

nunesaf said:

Oh I see !

As it is suggested in the link I sent, check the earthing before you get that module.

Good luck and keep us posted then

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Thank you for the link. I will definitely check out the earthing as well, and keep you posted on the latest developments.

You are absolutely correct TDC sensor doesn't apply to yours.
The finned box on the distributor would be my first suspect.

Cheers,
-Alex

Just thought that I would report back. I fitted a new CDI module, it wasn't even necessary to remove the distributor and took me all of five minutes to do. I'm happy to report that the problem has been fixed! Thanks again to everyone for their advice and replies.

Re: Fiat Uno 1.1 engine stalls at operating temperature

Call me tonight, fellow South African. Too long to type. Just solved the exact problem on my car, a 1989 Uno mk 1, carburettor.
Johan van Wyk
07754233671

MysticEntity said:

Just thought that I would report back. I fitted a new CDI module, it wasn't even necessary to remove the distributor and took me all of five minutes to do. I'm happy to report that the problem has been fixed! Thanks again to everyone for their advice and replies.

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Well done congratulations

I've owned my Uno 1100 for about seven years now and replaced the ignition module twice in that time. On both occasions it just died and I was stuck! My advice is to keep a spare module in the boot - just in case!

Darn! I've owned VW's for 20 years and never had any of these problems (when explaining my problem to the local auto electrician he comically replied "a Uno is a Fiat, and a Fiat is a problem by itself" couldn't help but laugh at that), luckily these modules are reasonably cheap to replace.

All Italian cars have a reputation for poor electrics. The nice thing with the Uno is that they are so simple to work on and the only electrical problem I've had in eight years of owning mine is this ECU on the distributor. When you compare the problems reported by a lot of new car owners, often after just a couple of hundred km's, the Uno is a very reliable car. I've found that it's better to pay a bit extra and use genuine Fiat parts when you can get them. A lot of people say the Uno has a bad reputation for reliablity and sure, if cheap, 'pirate' parts are used in some of the more critical parts of the car you will have problems. Better to pay the extra and use Fiat parts, they last longer too and in the long term you will save.

Hi there...yes it is definitely the ECU, or as my local spare shop calls it a module, uhm i had the exact problem with my uno (same as your uno), battled to find the problem but i replaced it for R 300..problem solved

I'm only glad that my car decided to break down literary a couple of meters from my home, I hate to think what trouble I would have been in if I were away on vacation somewhere.

As advised I will surely carry a new spare module with me since they are so easy to replace.

Hi there

I drive a fiat uno 1.1 model 99, my problem is that when I reach 60km / hour my gear lever becomes unstable, as if the rear mountain is not in place, I've changed all the mountains to no avail.. If u have any suggestions plz help

My Uno 1100, 1996 model is only cranking as if its gonna start. I just fitted new distributor&coil, it cranked & engine ran then it cut off after 12minutes. Now its only cranking, could be a module or coil because there is no spark coming into the distributor. Please help I love my car.

MysticEntity said:

Thanks for your reply. I'm from South Africa and Uno's were built here until about 2004. The last batch looking the same as the ones in Brazil.

Your'e correct about the CDI unit on the carburetor, that was what I was deferring to actually, I hear that they tend to go. I can get a new one at a reasonable prize, but the shop is situated in another town 60km away....

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hi..did u manage to sort this problem out?im sitting with the same problem!also from cape townn

smeags said:

hi..did u manage to sort this problem out?im sitting with the same problem!also from cape townn

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Hi, yes a new CDI unit fixed the issue. I managed to get a new one for less than R200. Installed it in less than 5 minutes. I bought a spare one for R120 that I carry with me in case of emergencies.