So I just saved a Cinquecento from the scrapyard.
Fresh APK (Dutch MOT), 2 months old head gasket, 99 pounds.
I was looking for a cheap runabout (no worries, I actually will take care of this little car) second car so the timing was perfect.

It drives well, except from some sticky brakes after heavy braking.
But once it gets up to temperature, it seems to go into some sort of emergency mode running rough and revving very slowly.
There's a light (injection?) burning on the dash. See attachement.

I've only driven it for 10 minutes and when warm so I don't know whether the light is on continuously, or comes on once the issue arises.
The owner said that it starts when the car comes up to 90 degrees celcius. It takes longer for the problem to begin in wintertime than in summertime.
Apparently as soon as it reachtes these 90 degrees the temperature drops to 70 degrees but the problem stays.
Acceleration is really slow, even when in neutral, top speed is around 60mph/100kph and the car smells of unburnt petrol.

You can actually search for "ZmkRgVTYQL0" on youtube. It will give you a (Dutch and rather chaotic) video I just shot and you can hear how slowly it accelerates and how rough it runs.
Also you can hear there's a problem with the brakes after heavy braking, they seem to 'stick' a little. Probably just greasing of the calipers, I guess we'll figure that out.

It seems as though some sort of error when warming up tells the computer to put the car in some emergency mode as soon as the car has warmed up.

I hope to fix this car as it's way too nice to scrap just yet.
It's only done 130.000km (80k miles) and I hope to be able to keep it running for a year or two. I love the way it drives otherwise, it's surprisingly stable and comfortable for such a tiny light car.

If anyone has any idea what's going on, that'd be lovely!

Thanks in advance.

Injector light = diagnostics software will tell you what is up. Software is for free, the cables cost peanuts on ebay.

Nevertheless, my guess crank position sensor failed. The warm=bad symptom is typical.

Did you service the car?

New oil ,filter, sparkplugs, cables, coolant, airfilter etc...
Al the sensors clean?

Where do you live in the Netherlands? ( i lve there to )

Greetings,
Maurice

@ Peanut01:
I just bought the car for 99 pounds so I don't want to spend too much without knowing what's wrong. A car like this can turn into a money pit so we don't want too spend too much money in 'guesses'. I know it's difficult to figure out what the problem is without replacing parts but since we only just got the car, we don't know what we are putting our money into yet .

The car does have clean oil, that's for sure, and new spark plugs.
We are, of course, going to clean the sensors after we have our manual so we won't have to guess where they are.

As for diagnostics; Turns out this car has ban OBD, not an OBD2. We still have to get an adapter. I do have the software (torque pro) and the bluetooth plug.

I live in the middle of Limburg myself, the Fiat is parked at my parents in Susteren, about 10km from my place.
Do you maybe know where I can best (cheapest & quickest) get a FIAT OBD to OBD2 adapter to check the ECU?
woj: So you think the sensor itself gets messed up from the heat?

Here's an update:

We just drove the car and watched closely what happens.
The weather was colder so it drove perfectly fine for a little longer than last time. The car goes faulty at 90 degrees C. Injector light starts burning at that moment and as soon as this happens the cars' temperature drops back to 70 degrees and stays there (according to the gauge, I can't check if that's correct)
This time though right after starting the car had about three seconds where it didn't run quite smoothly. The light went on then as well but this issue fixed itself.

What's probably notable is that though the gauge read 70, the engine felt remarkably cool. I wouldn't even call it lukewarm and we didn't exceed 50km/h so you'd expect it to be reasonably warm. The exhaust though was really hot.

Thermostat? Kathalytic converter? Any other ideas?

One more thing that might be interesting; The car gives a puf of smoke after starting. Probably oil. After that it runs clean and smells clean.
is this a normal thing with these cars?
It's the 1.1 with 130.000km on the clock.

Thanks again!

Torque Pro will not work, neither will any other mobile app, these ECUs are previous age, you need IAW ECU Scan running of a laptop.

I'd do a compression test too.

stijnkraft said:

The weather was colder so it drove perfectly fine for a little longer than last time. The car goes faulty at 90 degrees C. Injector light starts burning at that moment and as soon as this happens the cars' temperature drops back to 70 degrees and stays there (according to the gauge, I can't check if that's correct)

Click to expand...

Mine does that to... that means that your thermostat is working... Only my injectorlight does not come on. Maybe your tempurature sensor is fautly... this sensor give a signal to the ecu that your car is getting warm, and change the settings to the engine.

woj said:

Torque Pro will not work, neither will any other mobile app, these ECUs are previous age, you need IAW ECU Scan running of a laptop.

I'd do a compression test too.

Click to expand...

A compression test? Why? If it performs well when cold, why would you suspect compression problems?

Pity. I paid for Torque Pro. Oh well, who knows. May be able to make someone else happy with it .
Any idea where I can get the cable I need? Preferrably to USB but I do have a laptop with an LPT and COM port if needed .

Forget ecu scans, this is a Cinq.

Get a multimeter on the temp sensor and see what it does when the engine gets warm.

My guess is it still reading cold.

Cheers

D

Since I still don't have the Haynes manual in, can you tell me what it should read?
Also, is the car supposed to be running or just ignition on?
Same question for the Lambda sond by the way.

Wait, that was a rather stupid question. The car will have to run for it to become warm. Sorry. Question remains for the lambda sond though

Here's a little video from last saturday of me driving the car home:

[ame]https://youtu.be/ALLeVBFW8Ho[/ame]

The problem begins at 1:40 and if you keep watching you'll get a proper idea of what the car sounds like when running 'rough'. Also shows the extreme slowness .

Forget the lambda, its working fine.

The files will give you the actual readings, but all you are looking for is a reduction in resistance as it gets warmer.

Cheers

D

We took out both sensors while we were at it.
The actual temperature sensor (the blue one) does indeed lose resistance when you warm it up in your hands. Is that a problem or is that what it's supposed to do?

They both read about right.
How can you tell it's not the Lambda? Because it runs good cool?

My dad keeps suggesting the cathalytic converter, could that be the case indeed or is there a reason why it shouldn't/couldn't be?

So the question remains; If they both measure as they should, does that mean they are working as they should or is it still useful to replace them?

With all due respect for rallycinq - if there is injector light, hook up the ECU to the laptop.

To me it actually sounds like missing spark. You can disconnect the coils one at a time to see if it changes something. If not that's the fault.

Why would it stop missing spark all of a sudden (like 'instant', it doesn't cough, it just starts running rough) once it gets warm? Is that logical?
To me it runs too 'round' to miss a spark but it's an easy thing to test obviously.

As for the laptop part; I may check if my local garage wants to help me for that because I will need another cable for that again .
Or does anyone have an ebay link with free shipping for me? .

http://m.ebay.co.uk/itm/Fiat-3pin-O...-Diagnostic-Interface-Alfa-Fiat-/251603446444

This is the thing you need. Forget the software that comes with it (you'd still need the USB driver), use

http://iaw-scan2.sourceforge.net/

And also read there to confirm the cable, I could always get it wrong.

stijnkraft said:

We took out both sensors while we were at it.
The actual temperature sensor (the blue one) does indeed lose resistance when you warm it up in your hands. Is that a problem or is that what it's supposed to do?

Click to expand...

Thats what it is supposed to do, run the engine up to the point it begins to misfire, then check its resistance.

stijnkraft said:

They both read about right.
How can you tell it's not the Lambda? Because it runs good cool?

Click to expand...

It could be the lambda, the lambda is disconnected until the car is warm, though the fact that the lambda can 'see' the issue and is reporting the issue would lead me to look elsewhere.

stijnkraft said:

My dad keeps suggesting the cathalytic converter, could that be the case indeed or is there a reason why it shouldn't/couldn't be?

Click to expand...

Think the process through, the lambda is seeing an issue, that is either too much fuel or too little fuel. The exhaust passing through the cat is not of the correct quality.
If the temp sensor is reading incorrectly the engine will over/under fuel, the lambda will see that and send signals to the ecu to adjust to the correct ratio. If the ecu has run out of adjustment due to an incorrect signal, then the light comes on.

It could be a spark issue allowing unburnt fuel through, so needs checked.

Rule out the simple bits first.

D

Update;
We cleaned, exchanged and refitted a lot.
The plug that goes into the injector had a lot of play, that's fixed.
Then there's two cables (brown and black) leading to the air filter house. They were the wrong way around (Or exchanged we can't tell, anyone got any info on that?).
Then there's the thing the cables go to

Got two little holes. One of them was full of crap. Not anymore.
Both temp sensors (temp gauge and the one going to the ECU) exchanged.
Still have to measure the Lambda, but we found something out.

We started the car, had it Idle and it idle for an hour. It ran perfectly for that hour. In this hour the cooling fan stopped and started about six times, motor maintained 90c.

Then at some point the rough running started again and the car started smelling like unburnt fuel.
From that moment on the fan does NOT start anymore and the temperature stays around 80 degrees where you'd expect it to get warmer at some point.

Halp?

What did the engine temp sensor read at that point?

D