coolant temp & fueling relation

[dark_knight]

can anyone confirm that the stock ecu fuels more when the coolant temp readings are lower than half..? i would presume that would mean the coolant is at about 50~60 degrees when the gauge is at about quarter..?
i ask because i recently started digging around in order to know if i am burning more fuel because my engine is constantly running cool, from not having a thermostat.

 

[dac69er]

im not 100% sure at what levels the ecu fuels differently. but i would imagine it would fuel richer if the engine isnt getting up to its operating temperature.

 

[dark_knight]

it's very hot in my locale so i've been running w/out a thermo for a while.. and i like the way it keeps the engine cool after only a short run, esp in the mornings but after several members on here mentioned that it's bad for the engine to run below optimum temp as the oil stays cold - which is further bad for many other things, i'm getting cold feet about my setup so was wondering if that also further hurts my mpg.

 

[dac69er]

if it doesnt reach operating temp then no it wont be good for mpg.

how does the temperature behave with a thermostat fitted? does it maintain temperature or get too hot?

 

[dark_knight]

i just fitted my thermo today and so far it holds steady at slightly below the half mark so will run around with it for a couple of days and see how that goes. my rad fan is rather silent but will keep an ear out for it when in slow traffic to see if it kicks in when it's supposed to..

 

[Jay]

A false engine temperature reading can cause poor starting, increased fuel consumption and reduced engine performance. The ECU bases a lot of it's calculations on coolant temperature. If the cooling system isn't functioning properly then it will have a knock on effect.

Report back once you have run the car for a few days. Chances are it'll be much happier.

Jay

 

[dark_knight]

@Jay: already, i'm liking that my feet stay warm from the matrix heater in the mornings on my way to work.. hehehe. will also try watch my mpg and since i just recently changed oil (15w-40), will watch how quickly it stains as i figure these could be indicators of if something (else) was going wrong..

 

[MARK@CMBAUTOS]

buy a sard or trd low temp thermostat then ur car will run at 72'c instead of 86'c like it would from standard

also wat starlet do u have ? ep91? ep82 ?

 

[dark_knight]

i've got an ep91 v, p-sport and my thermo is set to pop at 82 degrees so i think that's ok..?
is running at 72 still going to be good for my oil and fueling/mpg..? that's the reason i plugged the thermo back in in the first place since i felt my mpg was suffering..

 

[dac69er]

are you talking about thermostat or a sensor? you dont plug in the thermostat???? or is it just your choice of words thats confusing things?

 

[MARK@CMBAUTOS]

i've got an ep91 v, p-sport and my thermo is set to pop at 82 degrees so i think that's ok..?
is running at 72 still going to be good for my oil and fueling/mpg..? that's the reason i plugged the thermo back in in the first place since i felt my mpg was suffering..

my car runs at 72'c with no issues rizes to around 78 when giving it beans !
then settles back to 72ish works a1

 

[dark_knight]

@dac69er: sorry if you don't have the history behind my situation.. my car was initially running without a thermo.. so i got one and installed it. sorry if by using the term 'plugged in', i made it sound like an electrical connector.. lol

 

[dark_knight]

@MARK@CMBAUTOS: i'm guessing you have a coolant temp gauge setup on your system..? perhaps that would be one of the goodies i could consider, alongside oil temp and oil pressure gauges..
what oil do you run on..? 10w-30..?

 

[Rev]

Texx did a great post that said
Cool cycle should finish at 45 deg C normal is 85 deg C
and 50 deg C should be half on temp gauge [ -20 deg C to 120 deg C being the gauge range ]

So if you are much below half on the gauge you should check for over fueling .

 

[dark_knight]

@Rev: i'm maybe only a stick under half so nothing to worry about i suppose. i noticed on the block that there are two temp sensors, one (3-wire) on the up-pipe that goes to the top of the rad and the other (1-wire) that goes on the joint right after the thermo which goes to the bottom of the rad. i was wondering from which of the two the temp gauge gets its' readings from..? or does the ecu do some math based on the readings it gets from both sensors..?

 

[Rev]

Craft I'm not up on those sensors thought there was the green one near the thermo for the ecu, but thinking about it the the radiator electrical fans and on mine are two speed for two different temperatures there is an ecu pin to raise engine rpm went fans come in with heavy voltage drop. As Jay said above a lot happens with water temp. the ecu has a set procedure for startup etc. has been posted before.

 

[MARK@CMBAUTOS]

@MARK@CMBAUTOS: i'm guessing you have a coolant temp gauge setup on your system..? perhaps that would be one of the goodies i could consider, alongside oil temp and oil pressure gauges..
what oil do you run on..? 10w-30..?

yes i have an Apexi pfc and Commander
i run silkoline pro s 5w40

 

[dark_knight]

how often do you change your 5w-40..?

 

[gorganl2000]

@Rev: i'm maybe only a stick under half so nothing to worry about i suppose. i noticed on the block that there are two temp sensors, one (3-wire) on the up-pipe that goes to the top of the rad and the other (1-wire) that goes on the joint right after the thermo which goes to the bottom of the rad. i was wondering from which of the two the temp gauge gets its' readings from..? or does the ecu do some math based on the readings it gets from both sensors..?

3 wire plug seems to go to the ecu (temp guage)
1 wire plug seems to go to the radiator fan

 

[weeJohn]

The gauge takes it reading from a sensor on the thermo housing, a different one from the ECU. The ECU sensor is a 3 wire as above, I am not up to speed on Glanzas that much but the gauge sensor is 1 or 2 wire. Start the car and look at the temp gauge, pull the plug off the 2 wire sensor and see if the gauge value changes. If you pull the plug of the ECU sensor all will happen is it will overfuel as it will think the resistance of the sensor is high so the temp of the coolant is cool, it wont damage the ECU.