Topic: Temp need

[Oilsmoke]

At what engine temp is needed for the ECM so will go into the closed loop circuit.?

[Oilsmoke]

Did I word this wrong? or nobody know the answer.

[aw12345]

Generally it takes 3 things to go in closed loop but the most important on newer engines is the oxygen sensor, atleast if it has a 3 or 4 wire sensor those start toggeling it will go in closed loop also the ecm has an internal timer that has to complete its cycle and ofcourse it has to warmup a bit but I would say the oxygen sensor is most important also if the beast is fuel injected stick with a 195 degree thermostat the cat will live longer and better fuel milage

[Oilsmoke]

I quess what i am looking for is the Temp level needed for the ECU to Go into Closed Loop Mode.
The O2 Sensor is not used unless you are Warmed up to that point. What is that piont. is it 180 or 190 etc...
On my ODB 1 ECU setup Closed Loop mode only is used in 2 of the 7 modes.
These modes are:
Deceleration
Cruise.
All other modes are in Open Loop which are a preset or Hard code programed into the ECU. SO if your engine runs too Cold it will never go into closed loop and the O2 sensor will never adjust A/F in crusie mode unless that Target temp is reached.
 Does this Sound correct if so  who knows what It Is.


YJMechanic do you know or can you find that Value?

[jfrabat]

All other modes are in Open Loop which are a preset or Hard code programed into the ECU. SO if your engine runs too Cold it will never go into closed loop and the O2 sensor will never adjust A/F in crusie mode unless that Target temp is reached.
 Does this Sound correct if so  who knows what It Is.

I dont know what it is, but I am watching this very closely, as with the new Taurus Fan, my YJ (also BD1) is running much cooler, and this may be affecting performance (I may need to run it a little hotter).

Felipe

[jdb1937]

I have run 180 degree water temp (i use 160 degree thermostats) for a long time, not just in my TJ, but in my GC with 4.0, riding lawn mower, Dodge dakota with 4.7 and etc.  My gas mileage stayed the same and no CEL from stock water temp (210-215) and current 180 degree temp.  This indicates to me the system is running in closed loop.  I could add a chip, advance the timing, and get better gas mileage. (will be soon)  There have been a LOT of benefits to running 180 water temp:  oil changes stretched out to every 10,000 miles, hoses and vacuum lines and belts dont wear out nearly as fast; never any pinging; A/C performs far better; no more blown head gaskets.  Heat is still great in the winter, because i always run electric fans  (flex a lite) which allow the engine to warm up quickly and i find that 180 degree water is plenty hot enough even for 20 degrees below.