Civic D15B(Exi) Idle issue

[hammi]

What is that? How to check that. Im sorry im a noob

[Hassan1991]

i don't know what they call it in desi terms. Maybe be lambda gauge. But good workshops have them.
They are actually wideband sensors gives more user friendly output i.e Afrs.

[hammi]

[hammi]

These are the reading im currently getting. I have put a 78 degree thermostat valve. Will that be enough to signal ECU that the car has reached optimum temp and it doesnt run rich?

The AT selector has not been wired. When I put the car in D4 the switch does not say ON on the scanner and neither do the solenoids work. I will get them wired.

Injectors are running at 2.7-2.8ms on idle with all electronics off. Is that correct reading?

[hammi]

Fan starts working at around 85 degrees. Isnt that too low?

[Hassan1991]

That's like 1.8-2 % duty cycle. Looks fine to me.
Honda engines operate between 82-87C temperature range. Your engine is cold. Install oem thermostat.
Compensation tables of ECT are divided according to temperature ranges
For example
At 20C 20% rich fuel
40C 10% rich fuel etc etc. Gradually comes to zero. But it's better to install oem things

[shabbir.1]

No, that's way too much low. Fan should kick in at around 95 °C. Possible culprit here is the fan switch, installed in the thermostat housing.
You can easily confirm the switch over temperature of thermostatic/ fan switch if you remove it from the housing.

[shabbir.1]

78 °C is the correct thermostat valve for D series engines, hope you have installed a brand new oem part.
ECU gets engine temperature reading from the ECT sensor installed separately near the gauge cluster temperature sending unit.

Injectors duration is slightly on the higher side, but it might be the correct range for an engine coupled with auto transmission or the engine is running cold.

MAP reading is also in the correct range, which suggests that there is no uncontrolled air leaking inside the manifold.

Apparently the only worrisome thing here is the ECT reading, it should be cycling between 88 and 95 with auto fan while the engine is idling.

[hammi]

The engine was cold then. After driving a bit the fan turned on at 86 degrees. The temp stays between 83-87 degrees. I’m confused if this is the correct range but injectors are running at 2.8ms. My Lancer has injectors running at 2.0ms. It might be different for every car.
Average seems to be better now.
Its giving a VSS code now. Needs a speed sensor now. 🤦‍♂️

[hammi]

My lancers temp stays between 92-97 degrees. Im not sure about honda a mechanic said I need to change the fan switch the Chinese fan switch operates at around 85 degrees. Im not sure whats the correct temp for this engine

[shabbir.1]

There is definitely something wrong with either the thermostat/fan switch or the ECT itself. As I said earlier you can easily verify the working of fan switch after removing it from the housing.
Before changing the VSS, check the wiring integrity and also the voltages on different wires.

[shabbir.1]

Upper end of the engine temperature is maintained with the help of radiator fan (engaging automatically).
And the fan operation is controlled by fan switch or the ECU, both provides parallel ground paths to the radiator fan relay coil (the later is non functional on most ECUs versions)

On most D series engines fan switch behaves like:
ON = 91 - 95 °C
OFF = 3 - 8 °C lower than the temperature when it goes on.
e.g., if it turns on at 95°C then it will turn off at 88°C.

If you want to replace the switch, find a new genuine or Japanese part avoid cheap Chinese knockoffs.

[hammi]

The VSS is not connected at all I think. Because the speed always remains zero on the ECU.
I will search for a Japanese fan switch. The original thermostat that came out of the car also had 78 degrees written on it.
I don't know where to check the original thermo reading for this engine

[hammi]

If I remove the fan switch from the housing how will the fan work? I dont understand how to conduct this test and what will it check

[Hassan1991]

Honda engines run cooler then toyota. This is where toyota engines work.

[hammi]

Mitsubishi engines run at hotter temp too Im sure. Okay so its a Honda thing. What should be the advance timing at idle(750rpm) im seeing 12-14 degrees. Shouldnt it be 9-11 degrees?

[Hassan1991]

@shabbir.1 might be right with temperature range. still cooler then toyota.
i had k series in my mind..
timing is fine at idle.

[shabbir.1]

I think you are confusing thermostat valve rating with that of thermo/fan switch.
Mostly standard honda thermostat valves are rated at 78°C. This value actually indicates the opening temperature of thermostat valve.

Standard honda thermostat valve behaves as follows:
start opening = 78°C+/_ 2°C
fully open = 90°C
lift height = 8.0mm

[shabbir.1]

You only need to remove it for testing or replacement purpose also you are not supposed to start the engine during this period. Some coolant will be lost while removing the thermo switch so you must ensure to replenish the coolant level afterwards.

To test the thermo/fan switch you need the following:
a. multimeter set on continuity/beep with mini size crocodile clips.
b. digital thermometer with metal probe suitable to measure hot water temperature
c. a metallic pot (or any household utensil)
d. thermo switch under test
e. cotton thread for hanging thermometer probe and also the thermo switch

Attach the crocodile clips of multimeter with each of thermo switch terminals (clips should not touch each other) and set the multimeter on continuity or beep reading. Now using cotton thread and any commonly found kitchen items to tie and hang temperature probe and the thermo switch inside the pot. Fill the pot with water but water should not reach the terminals of the thermo switch and also make sure that the thermometer probe and the thermo switch do not touch the pot base.
Put the pot on gas burner and wait till the temperature rises up to 94°C. The multimeter shoud sound continuity beep as soon as the tenperature reaches 94°C.
Turn off the gas burner and wait till temperature drops below 88°C, the continuity beep should stop at this point. Repeat this procedure at least one time more to confirm the working of thermo switch.
On the same principle you can check working of thermostat valve as well.

[hammi]

Got it! I will get it checked that way too. If the scanner is showing the engine is at 85 degrees and the fan turns on isn’t it the same thing? It means the engine thermo fan switch starts working at 85 degrees. I will come back to it again. I checked the plugs they have turned brown now. Im happy for now thermostat and fan switch arent a big deal.

The car is missing a VSS. The gear does not has a VSS. It has a mechanical wire coupled with the meter. I have heard there are VSS which have socket for mechanical wire too. Will search for the VSS.

Another problem is ECU is not connected with gear selector. I searched for P2C pinout but not sure if its pin 16 or pin 22. If someone can help it will be great.
The gear selector is under the gear lever. Can I take a wire out from the D4 switch wire and connect to the ECU? The wire is ground(-12volts i think)