Ford Zetec 1.6 Cold idle
Discussion
When started from cold the idle is far from smooth and hunts from 1100-1500 when stationary. The area above the tailpipe seems unduly sooty.
Until the engine is warm it continues to do so. I can only compare it to driving with too much choke, perhaps suggesting that the management is overcompensating for cold starting ?
Once the engine has warmed up the idle is smooth and steady.
The dealership is giving the 'they all do that, sir' line, but I have driven a 1.8 which did not have this problem
Can one check the idle air control valve ?
Until the engine is warm it continues to do so. I can only compare it to driving with too much choke, perhaps suggesting that the management is overcompensating for cold starting ?
Once the engine has warmed up the idle is smooth and steady.
The dealership is giving the 'they all do that, sir' line, but I have driven a 1.8 which did not have this problem
Can one check the idle air control valve ?
cheapest thing to do is replace the ECT sensor.
Thats the engine coolant temperature sensor.
Possible that the engine management is thinking the engine temp is colder than it is, and then over fueling (giving the on choke feeling).
the sensor is cheap, but DON'T over tighten it in it's housing.
If the engine is smooth at warm/hot idle i'd leave the IAC valve alone for a while, but if you want to fiddle with it, a good clean with brake cleaner won't do any harm.
Thats the engine coolant temperature sensor.
Possible that the engine management is thinking the engine temp is colder than it is, and then over fueling (giving the on choke feeling).
the sensor is cheap, but DON'T over tighten it in it's housing.
If the engine is smooth at warm/hot idle i'd leave the IAC valve alone for a while, but if you want to fiddle with it, a good clean with brake cleaner won't do any harm.
The lamba sensor could also be playing up and be reading low, this would cause the engine to run rich. On the eec IV ecu when it gets past 3000rpm the ecu ignors the lamba sensor and soly uses the mass air flow sensor and air charge temp sensor. i also agree with the ect might be playing up, thay have a habbet of doing this. hope this helps
Nah
At cold running the car wont have entered into closed loop control and as such won't look at the hego signal.
The hego does switch above 3000rpm, I think your getting confused with the wide open throttle condition(WOT), when that is detected the EEC IV reverts to fixed maps within it using the sensors you described as a reference value.
think about the 3k rpm bit........Escort 1.6 (90ps) zetec cruises 70mph @3200rpm
I still think it's a sensor fault on the basis of the present information
At cold running the car wont have entered into closed loop control and as such won't look at the hego signal.
The hego does switch above 3000rpm, I think your getting confused with the wide open throttle condition(WOT), when that is detected the EEC IV reverts to fixed maps within it using the sensors you described as a reference value.
think about the 3k rpm bit........Escort 1.6 (90ps) zetec cruises 70mph @3200rpm
I still think it's a sensor fault on the basis of the present information
nighthawk said:
cheapest thing to do is replace the ECT sensor.
Thats the engine coolant temperature sensor.
Possible that the engine management is thinking the engine temp is colder than it is, and then over fueling (giving the on choke feeling).
the sensor is cheap, but DON'T over tighten it in it's housing.
If the engine is smooth at warm/hot idle i'd leave the IAC valve alone for a while, but if you want to fiddle with it, a good clean with brake cleaner won't do any harm.
Yeah first port. They dont hunt around overly much as you prescribed from your 1.8 so go with Nighthawk for the first step. Failing that try a specialist ford engine company! Mountune may help a little?
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