Bad Coolant Sensor

[George k11]

Hello to all

I need same help here

When i start the engine it stays for at least 10-15 min with high rpm. The weather temperature here in Cyprus is 30-35 degrees . Is this normal ?
Also i notice and a high fuel consumption 9.5L/100 km in town driving. (Normal driving) i Thing i VERY high

Is it possible the high fuel consumption caused by the coolant sensor ?

Thanks

 

[SuperUno]

Is the rad fan running all the time? If yes this is a sign the coolant sensor has failed. If not more likely to be a TB problem.

 

[pollyp]

the prolonged fast idle sounds like:
- ecu coolant sensor (2-pin plug) is reading wayy too cold (ie very high Ohms or broken circuit), making the ECU run on rich cold mixture & opens IACV for fast idling till the sensor reads warm & Ohms reduce.
remove the sensor and test it's resistance in hot water against this chart
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-119#post-704079

- old fast idle waxstat cam mechanism sticking/seized on till the hot coolant moves it enough to close the throttle after 15min.
remove the old primative fast idle cam mechanism cos IACV does the same job electronically
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-19#post-446256

- dirty stuck IACV
remove & clean the dirt/soot off the IACV
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-19#post-446256

low economy could be:
- old worn lazy O2 sensor.
- old worn ECU coolant sensor making it run too rich. remove & test sensor resistance.
- blocked filters. replace if overdue or appear dirty.
- dirty MAF. spray clean with carb cleaner.
- bad spark. check spark plug condition & appearance as a sign of combustion status. check gaps.
- bad worn compression. test compression are all even & within 11-13bars
- binding brakes. lift & spin each wheel for any drag
- uninflated tyres
- misaligned wheels. check tyre depths for uneven wear
- high drag from open windows or aircon
- driving style

 

[davyboy]

Pollyp ......you the man

 

[George k11]

Is the rad fan running all the time? If yes this is a sign the coolant sensor has failed. If not more likely to be a TB problem.

SuperUno
No the fan does not running all the time !

 

[George k11]

the prolonged fast idle sounds like:
- ecu coolant sensor (2-pin plug) is reading wayy too cold (ie very high Ohms or broken circuit), making the ECU run on rich cold mixture & opens IACV for fast idling till the sensor reads warm & Ohms reduce.
remove the sensor and test it's resistance in hot water against this chart
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-119#post-704079

- old fast idle waxstat cam mechanism sticking/seized on till the hot coolant moves it enough to close the throttle after 15min.
remove the old primative fast idle cam mechanism cos IACV does the same job electronically
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-19#post-446256

- dirty stuck IACV
remove & clean the dirt/soot off the IACV
https://www.micra.org.uk/threads/pollymobiles-rebuild.35251/page-19#post-446256

low economy could be:
- old worn lazy O2 sensor.
- old worn ECU coolant sensor making it run too rich. remove & test sensor resistance.
- blocked filters. replace if overdue or appear dirty.
- dirty MAF. spray clean with carb cleaner.
- bad spark. check spark plug condition & appearance as a sign of combustion status. check gaps.
- bad worn compression. test compression are all even & within 11-13bars
- binding brakes. lift & spin each wheel for any drag
- uninflated tyres
- misaligned wheels. check tyre depths for uneven wear
- high drag from open windows or aircon
- driving style

Pollyp
Thanks A lot man !!!! U R professor

 

[George k11]

Is the rad fan running all the time? If yes this is a sign the coolant sensor has failed. If not more likely to be a TB problem.

TB problem.??

 

[wehey]

TB problem.??

Throttle Body

 

[George k11]

Throttle Body

okeis
Thanks