Technical IAW 6F vs 16F ECU, closed loop minimum temperature

[Frank Folker]

Hello, i have several puntos, 2 of them with 1.1 55 engine.
My previous one was a 1996 55s with IAW 6F ECU (rear ended but I still have it for parts) and my current punto is a 1998 55 6speed with 16F ECU.

I did some testing using IAWscan2 software and found a difference in that the earlier 6F car entered closed loop operation much sooner after a cold start, at around 50°C reported coolant temperature, while the newer 16F car needs 81°C to enter closed loop.

Currently it's very cold in my country and I'm doing lots of relatively short trips, heat blasting as soon as it gets acceptably warm so it takes some time for the car to reach operating temperature (up to 10 minutes). By that time i'm almost done with my trip so i spend most of it in open loop with notably higher fuel consumption than in my older punto.
I think this difference in minimum temperature for closed loop operation is one of the reasons for higher fuel consumption in my case.
IAT and MAP sensors report expected values so I think they are not the problem. Thermostat is also working fine, once it reaches operating temp it stays there regardless of driving conditions, it's just cold outside so it takes some time to reach it.

Are there any other differences between 6F and 16F ECUs and are they interchangeable? (i know i would also have to transfer immo, code reader and key)

 

[blu73]

Couldnt say if there are other differences but if you swap the ecu and code system over it will run the engine just fine.

If you want to test it before swapping everything over, just plug the code box from the old one in, take the antenna from the ignition barrel too and just plug that in on the the new, leave the antenna just dangling and tape the matching key to it, and just plug the ecu in. That way you will be able to run the car as a test. If you are happy then go ahead and swap the ignition barrel over so you can use the matching key.