Fiat Punto 1.2 8V cutting out - strange problem

[omglol]

Hi!

The car in question is Fiat Punto 1.2 8V, make year 2004 with Marelli 5AF ECU. The ecu was repaired for common ignition coil error, but the problem is still here:

The car will run normally, no misfires, fine acceleration, everything absolutely fine ... until all of a sudden it cuts out, MIL comes on and following errors in the picture are stored. After that you have to wait a while, it starts and runs fine until next cut out ... which comes at unexpected time.

For example, yesterday I went for a ride ... 25 km went fine, then cut out. I had to wait 5 minutes, then it started again and I came home (another 15 km) without incidents. Today I went for a ride ... half an hour (don't know the mileage), everything fine, did not cut out.

Strange thing is that it always throws 4 fault codes ... and never runs just on 2 cylinders, like these usually do. Also I do not believe that in 5 mins (which you have to wait until it starts again) anything cools down ... as it would also heat up and fail again in 5-10 minutes ... which does not. It then runs just fine for 20 minutes or even more (did not test long enough to get second cut out on same test ride).

What do you suggest?

[sepistar]

i would check as first the knock sensor,maybe faulting,and causes that problem.
regards

[omglol]

Well wiring of knock sensor has nothing to do with ignition coils ... also fault is "signal low", not "short circuit" or something similar ...

[Tuiken]

Hello try change the Spare plugs May cause bloqued the ecu sorry My bad english

[omglol]

Spark plugs are not faulty.

[cactikid]

i better not mention crank sensor when faulty and hot car cuts out.

[omglol]

Then there would be crank sensor fault or no fault at all ... but not ignition coil pack fault ...

[smirnoff_rules]

sounds like your new/repaired ecu is faulty .. dry joint in it

[omglol]

Yeah, that would be the most reasonable explanation ... I will try to find a new one.

[Tuiken]

One day I have a punto 8v and he have the same problem the motor stop running and the only way to start motor is waiting 10 minutes or disconnect and connect the battery the problem is the spares she's induction a interference in the cables and the ecu blocked some issues happens in Fiat stilo 1.6 16V

[sepistar]

Well wiring of knock sensor has nothing to do with ignition coils ... also fault is "signal low", not "short circuit" or something similar ...

you can also check ecu connector and ground.
regards

[smirnoff_rules]

if u do change your ecu its best to change coil packs too, as there the reason the ecu's pack up

[omglol]

One day I have a punto 8v and he have the same problem the motor stop running and the only way to start motor is waiting 10 minutes or disconnect and connect the battery the problem is the spares she's induction a interference in the cables and the ecu blocked some issues happens in Fiat stilo 1.6 16V

Sorry mate, I don't understand you a thing ... almost like trying to understand boomhauer.

Stilo 1.6 16V has different issues ... MCU problem in ECU.

[Tuiken]

sorry my english I'll try again. I had a problem in the same car the engine shut off and only started after connecting and disconnecting the battery. and the problem was the spark plugs they induce some interference in the wiring that blocked the ECU. this same problem affected the fiat stilo 1.6 16V

[frankharrison]

Had same problem on my Fiat Multipla .
Ran for about 10 minutes then cut out and was a git to start.
Leave it about 10 minutes and it would start and be ok for about 30 minutes then cut out.
Turned out to be crank sensor.
The crank sensor tells the ecu where the pistons are.
If the sensor is faulty it'll not give the ignition time to charge before firing.
Mine even tested ok.
A new one sorted it.
Luckily my car was on a warrenty.
For the Punto I've seen them for aroun ?20 ish on E**B*Y.
Fairly easy to fit.