Tziallas
New member
I have a Punto 75 SX M reg (95)and had the following problems
1) At idle the revs where not stable
2) Could not hold revs at certain rpm
3) Excessice CO emissions
4) A hesitation at 3000rpm and then a sudden surge of power like turbo
Problems 2&3 where found at the recent MOT test,and the tester suggested that was the throttle position sensor, becasue the lambda sensor was OK (the limits 0.98 to 1.03 mine was 1.01)
A friend suggested this site a some of you suggested that could possible the temperature sensor.
I was confused and did not want to pay for fault read test (from 40 to 60 £ per hour)
I decided to call a friend from my origin country specialising in Alfa Romeos and FIAT's.
I told him the symptoms and he categorically said it was the lambda sensor, I replied that was inside the limits and yet insisted that was lambda sensor. He even decided to pay for the sensor if was not the problem.
His own words were "if the revs are not steady and fail in CO emissins and not in HC emmissions then it is lambda sensor... a lot of FIATS have that problem. The problem is caused that the sensor is 'slow' (picking the signal right but not responding accordingly)"
I bought the lambda sensor (original £65, non-original £55, I opted for the orignal) and changed it. The changing is very easy and straightforward, a 22 spanner a screwdriver is all you need.
The problem was solved and passed the MOT.
So if anyone has the same symptoms then it is the lambda sensor even if it reads OK
I decided to share my story in the forum in order to help other Punto owners but I don not imply that this is the solution to all cases
I hope that I gave some help
1) At idle the revs where not stable
2) Could not hold revs at certain rpm
3) Excessice CO emissions
4) A hesitation at 3000rpm and then a sudden surge of power like turbo
Problems 2&3 where found at the recent MOT test,and the tester suggested that was the throttle position sensor, becasue the lambda sensor was OK (the limits 0.98 to 1.03 mine was 1.01)
A friend suggested this site a some of you suggested that could possible the temperature sensor.
I was confused and did not want to pay for fault read test (from 40 to 60 £ per hour)
I decided to call a friend from my origin country specialising in Alfa Romeos and FIAT's.
I told him the symptoms and he categorically said it was the lambda sensor, I replied that was inside the limits and yet insisted that was lambda sensor. He even decided to pay for the sensor if was not the problem.
His own words were "if the revs are not steady and fail in CO emissins and not in HC emmissions then it is lambda sensor... a lot of FIATS have that problem. The problem is caused that the sensor is 'slow' (picking the signal right but not responding accordingly)"
I bought the lambda sensor (original £65, non-original £55, I opted for the orignal) and changed it. The changing is very easy and straightforward, a 22 spanner a screwdriver is all you need.
The problem was solved and passed the MOT.
So if anyone has the same symptoms then it is the lambda sensor even if it reads OK
I decided to share my story in the forum in order to help other Punto owners but I don not imply that this is the solution to all cases
I hope that I gave some help