Technical Engine stalling issue - Punto Evo 1.4 8V

[Jostein]

Good evening all.

We have some electrical issues on our Punto Evo which are turning into a long term drama.

In short, new error messages started turning up on the instrument a while back - "fuel cut-off unavailable" among others.

As the engine starts running rough on idle and then switches itself off, I took it to our local garage - which is an ex-FIat garage. They took the car in, found that the steering angle sensor was playing up, but as this really is an old issue which doesn't affect the operation of the car (as the steering servo still works fine) I asked them not to remedy this.

However, occasionallt the engine will start running rough when slowing speed into a junction or other, and this "fuel cut-off" warning will always light up before this rough running and subsequet stalling occurs.

The local garage has had this engine stalling issue happening to them on a couple of occasion when testing the car, but couldn't solve it - and sent me to an official Fiat dealer an hour drive away from us. I got the car back last Friday after leaving it with the Fiat garage for some fve weeks or thereabouts - where they have tested it in between other jobs, and even had this issue occuring on a few occasions. But they didn't find any clear answer as to why it occured, and no avtual repair has been done.

I am convinced this is an electrical issue of some sort. Have any of you encountered similar issues in the past, please?

 

[the green vanper]

Hello,

Search with the "fuel cut-off unavailable" text on the forum. I am quite sure have seen it several times here. But on other models. As far as I remember, it was the earth or batter issue. Earth strap body to gearbox (or engine) and its mounting on the body is a common problem on the FIATs. Replace it with good quality copper welding wire, get it cut to length from a local welding hardware shop. They should also be able to crimp thick terminals on both ends. Just bend them to fit the car and add heatshrink on the connection.

For battery health, go to a battery specialized workshop and test it for health on a LOAD tester (not the fancy electronic one).

 

[GrandePunto PL]

Clown world. Fiat "specialist" can't pinpoint the problem? And we will fix it via Internet? Right...
Yes, it can be electrical problem (or electrical-mechanical combination).
But mostly BASIC things to check (HOW do you perform the "checks" makes a difference).

Standard Fiat issues: bad battery, bad alternator (yes it can stall the engine and make CAN modules go crazy, like a Steering, AirBag - it triggers the fuel cutoff by the way), bad main ground and main fuse/relay box, ABS pump connector corrosion. Switches like a brake and clutch pedal signals.
Some of the electrical stuff should be diagnosed using oscilloscope (multimeter is often not enough). It's about waveforms (not just value on the multimeter or pressure gauge).

Mechanical: valve clearance/lash (all 8V Fire engines). And timing (to verify use MES, first VVT1 position should be about 106 degrees, then if camshaft real and desired positions are following each other = roughly you have a good timing/VVT system). Check (see) how the phonic wheel is running (if it's wobbly, has runout).

OBD2: some problems may pop during a test drive, take some data log (2-3 sets of parameters = you can't log ALL of them at once, or you loose "resolution" rendering data useless). But it takes a knowledge to interpret the data (and you must know when to stop and change the method, tool = oscilloscope).

Real Diagnostics is done like that (not exactly DIY).
https://www.youtube.com/c/AutomotiveTestSolutions/videos
https://www.youtube.com/@ScannerDanner/videos
https://www.youtube.com/@PineHollowAutoDiagnostics/videos
https://www.youtube.com/@realfixesrealfast/videos
Long story short: OBD2 data logs + mechanical/electrical basics + oscilloscope + exhaust gas analysis. This is how you repair any car.

Plus official sevice news, campaigns, recalls. This is for Grande, not Evo, but you get the idea (but some problems are shared between Grande/Evo).
https://aftersales.fiat.com/elearnsections/main.aspx?nodeID=199001626&languageID=2&markID=1&modelID=199000000&valID=199000001&prodID=199000000&modelName=Fiat - 199 - Grande Punto&langDesc=English&sectionName=Service News&validityName=1.4 8v&isExaminer=
Switch the engine type, the list of problems will change (each type has it's own issues, quirks). There are many related to the rough running etc.

 

[Jostein]

Hello,

Search with the "fuel cut-off unavailable" text on the forum. I am quite sure have seen it several times here. But on other models. As far as I remember, it was the earth or batter issue. Earth strap body to gearbox (or engine) and its mounting on the body is a common problem on the FIATs. Replace it with good quality copper welding wire, get it cut to length from a local welding hardware shop. They should also be able to crimp thick terminals on both ends. Just bend them to fit the car and add heatshrink on the connection.

For battery health, go to a battery specialized workshop and test it for health on a LOAD tester (not the fancy electronic one).

Many thanks for that! I've replaced the battery twice (yes, two new start-stop batteries) as well as had the alternator replaced with a new one, but I hadn't suspected the earth to body wiring. Many thanks for the tip.

 

[Jostein]

Clown world. Fiat "specialist" can't pinpoint the problem? And we will fix it via Internet? Right...
Yes, it can be electrical problem (or electrical-mechanical combination).
But mostly BASIC things to check (HOW do you perform the "checks" makes a difference).

Standard Fiat issues: bad battery, bad alternator (yes it can stall the engine and make CAN modules go crazy, like a Steering, AirBag - it triggers the fuel cutoff by the way), bad main ground and main fuse/relay box, ABS pump connector corrosion. Switches like a brake and clutch pedal signals.
Some of the electrical stuff should be diagnosed using oscilloscope (multimeter is often not enough). It's about waveforms (not just value on the multimeter or pressure gauge).

Mechanical: valve clearance/lash (all 8V Fire engines). And timing (to verify use MES, first VVT1 position should be about 106 degrees, then if camshaft real and desired positions are following each other = roughly you have a good timing/VVT system). Check (see) how the phonic wheel is running (if it's wobbly, has runout).

OBD2: some problems may pop during a test drive, take some data log (2-3 sets of parameters = you can't log ALL of them at once, or you loose "resolution" rendering data useless). But it takes a knowledge to interpret the data (and you must know when to stop and change the method, tool = oscilloscope).

Real Diagnostics is done like that (not exactly DIY).
https://www.youtube.com/c/AutomotiveTestSolutions/videos
https://www.youtube.com/@ScannerDanner/videos
https://www.youtube.com/@PineHollowAutoDiagnostics/videos
https://www.youtube.com/@realfixesrealfast/videos
Long story short: OBD2 data logs + mechanical/electrical basics + oscilloscope + exhaust gas analysis. This is how you repair any car.

Plus official sevice news, campaigns, recalls. This is for Grande, not Evo, but you get the idea (but some problems are shared between Grande/Evo).
https://aftersales.fiat.com/elearnsections/main.aspx?nodeID=199001626&languageID=2&markID=1&modelID=199000000&valID=199000001&prodID=199000000&modelName=Fiat - 199 - Grande Punto&langDesc=English&sectionName=Service News&validityName=1.4 8v&isExaminer=
Switch the engine type, the list of problems will change (each type has it's own issues, quirks). There are many related to the rough running etc.

Thanks a lot for momentous input! Most appreciated.

Yes, having asked in essence two successive Fiat garages to diagnose and repair it has left me somewhat disappointed, I have to say.

Having just on street parking and no garage, plus a busy day job, it all makes it difficult to dive into the problems myself - hence trusting the franchised service network..

I short, issues started in November when the car wouldn't start. A new alternator and two new start-stop batteries later - as well as three repair bills, we're still in the deep end.

I will check what I can myself and then have a word with the Fiat garage. They've had the car in for about five weeks, and I only picked in up on Friday last week - only for the problems to return in full on Sunday.

Cheers. I will go through all your info