HELP! ECUtalk readings r33 gtst

[dtrants]

HELP! ECUtalk readings r33 gtst

Hey guys,

 

Got an ECUtalk consult cable delivered today. Sorry for the bad quality photo, had to take it on my phone because the screenshot and video functions on the computer weren't working.

 

I was wondering if anyone was able to tell if any of these readings are off. The car was sitting at idle when the photo was taken. I had driven it around for around 20mins to get it warmed up beforehand.

 

Not sure if the O2 sensor and the Fuel pump S/V and F/B O2 Lean readings are correct as i don't know what they are meant to be?

 

Any information you can provide on any of these gauge readings would be greatly appreciated!

 

Thanks, (will try and provide additional photos/videos if needed)

dtrants

[dtrants]

incase you can't view the Gauge readings, they are as follows:

RPM- 1152

Timing BTDC- 5

Airflow V- 1.48

O2 sensor V- 0.02 (started at 0.2 and gradually dropped down to 0.02 within 20-30min)

Injector mS- 2.65

AAC%- 20

Fuel Pump S/V- 1

F/B O2 lean- 1

throttle V- 0.46

Battery V- 13.68

 

 

 

 

 

[KiwiRS4T]

I don't know much more than you but starting with the easy ones idle should probably be more like 800 (assuming the engine is warmed up) timing about 15 deg.  I believe the O2 sensor should be flicking up and down within a narrow range so a steady reading probably means its stuffed.

[dyl33]

1 hour ago, dtrants said:

incase you can't view the Gauge readings, they are as follows:

RPM- 1152

Timing BTDC- 5

Airflow V- 1.48

O2 sensor V- 0.02 (started at 0.2 and gradually dropped down to 0.02 within 20-30min)

Injector mS- 2.65

AAC%- 20

Fuel Pump S/V- 1

F/B O2 lean- 1

throttle V- 0.46

Battery V- 13.68

 

 

 

 

 

I have limited knowledge also but

Airflow V- 1.48 = AFM Voltage

O2 sensor V- 0.02 =O2 sensor Should flicker full range of the gauge when giving it throttle, I don't believe it does much at idle.

Injector mS- 2.65 = injector latency

AAC%- 20 = Aac should be open, at warm idle should be around 20, too high and can have trouble catch stalls and things

Fuel Pump S/V- 1 = fuel pump s/v will either say 0 or 1, 0 indicates solenoid valve is not active. 1 indicates your solenoid valve is active

F/B O2 lean- 1 ?

throttle V- 0.46 = TPS voltage, closed throttle = 0.44-0.46 ok, wide open throttle voltage 4.5-5v ok

Battery V- 13.68 = battery voltage

 

 

[dtrants]

4 hours ago, dyl33 said:

I have limited knowledge also but

Airflow V- 1.48 = AFM Voltage

O2 sensor V- 0.02 =O2 sensor Should flicker full range of the gauge when giving it throttle, I don't believe it does much at idle.

Injector mS- 2.65 = injector latency

AAC%- 20 = Aac should be open, at warm idle should be around 20, too high and can have trouble catch stalls and things

Fuel Pump S/V- 1 = fuel pump s/v will either say 0 or 1, 0 indicates solenoid valve is not active. 1 indicates your solenoid valve is active

F/B O2 lean- 1 ?

throttle V- 0.46 = TPS voltage, closed throttle = 0.44-0.46 ok, wide open throttle voltage 4.5-5v ok

Battery V- 13.68 = battery voltage

 

 

Hey mate,

Thanks heaps for that info! Would you happen to know, looking at my readings, whether or not they are in normal range? 

dtrants

[dyl33]

I'm not 100% sure, it looks ok except for the timing btdc 5deg seems odd for idle, stock should be 15deg @ 650rpm which it says under the bonnet. What this mean I don't know.

[zoomzoom]

Could be extra unmetered air making it into the engine. Hence the high idle rpm and the ECU trying to bring the rpm back down with low timing.

Or the screw on the AAC valve could be improperly adjusted allowing too much air in at idle, causing the above symptoms. Try adjusting the screw first to bring the idle down.

[dyl33]

Snaked this from somewhere else it might help.

"Voltage - the voltage the ECU is being supplied with.*
Expected values: around 12V when car isnt running, around 14v when its running.

Injector %: The duty cycle, or percentage of time the injectors are open for. If this hits 100% then it means the injectors are open continuously. This isnt necessarily dangerous if you're running really rich AFR (air fuel ratios), because you'd need to make a bit more power past the 100% mark before you lean it out to a dangerous AFR. still worth dyno checking etc if you're hitting 100% a lot.*
Expected values: At idle this should sit at 1-3%, above this should roughly correspond to how much load the car is under, normally cruising/light loads you wont get much above 20%. Note: some cars may have 2 'banks' of injectors.

Timing (degress BTDC): how many degrees (of a circle, rather than temperature ) before the cylinder reaches TDC (top dead centre, maximum compression) that the spark plugs ignite the mixture. Some peoples first thought might be wouldn't you just ignite at the top? the reason you need to ignite before the top is because combustion takes time to propagate through the cylinder, so you want to give ignition a bit of a head start so maximum pressure occurs at the start of the down stroke.*
Expected values: generally the values should be > 0 (i,e, BTDC rather than after TDC, ATDC). this can be quite low at cold start up maybe jumping around like 3-10 degrees depending on car. Generally timing increases with RPM (at same load) and decreases with load (at same RPM).

AAC: Auxilliary Air Control, is what allows air into the engine bypassing the throttle (otherwise the car would stall when you take foot off throttle if it was the only way for air to get in), in addition to the air allowed in via setting of idle screw (i dont know if that air goes in via same valve or what). basically this valve is controlled by the ECU and can open to raise idle (e.g. when aircon is on), often will be used to 'catch' a fast dropping RPM so you dont stall, etc.*
Expected values: when the car is warm and at idle, this shouldnt read higher than around 15-25, any higher indicates that this valve is making up for an incorrectly adjusted idle screw (i.e it has to compensate by being continually open more, this is bad because it means it has less room to move, e.g. to 'catch' falling RPM, etc). I personally had warm idle AAC value up at 50-60 once, and this resulted in the car stalling when being started when it was warm (AAC couldnt catch the falling revs after start motor stops).

O2 Sensor: oxygen sensor, measures whether the mixture of exhaust gases is either 'too rich' or 'too lean'. it doesnt really measure the AFR itself, because its narrowband sensor, and as such is more just a switch saying one way or the other, and the ECU uses it like this - when the car is under light load/cruising/etc conditions, it will continually adjust the fuel so as to hover around the 14.7:1 stoich mixture (or whatever the ECU/o2 sensor combination is targetting) ratio.*
Expected values: when the car has warmed up, and is cruising along at light load, this should be swinging back and forth from 0.1v to 0.9v or there abouts. if the sensor remains at 0v or 0.3v (or fixed at any other value, these are just most common), then it is dead. Note: some cars may have 2 x O2 sensors.

Temperature - the coolant temperature of the car.*
Expected values: up around 80-95C (depending on car and fan turn on/off values) once warm. You dont want this too low (e.g. if thermostat stuck open) as the car doesnt run efficiently when cold.

AFM - air flow meter: sensor that measures how much air is coming into the engine, which is generally synonymous with 'load' on the engine. this isnt necessarily linear measurement.*
Expected values: i think this reads about 0.3v? when the engine is off, a bit over 1v when engine is idling, and up to 5.1v (full measurable load of AFM, but you still may draw more air past this point, which may lead to fueling/mixture problems? some (all?) cars may have fuel/ignition cuts once the AFM maxes out? Note: some cars may have 2 x AFMs

TPS - throttle position sensor. measures how much the throttle is open. ECU uses this to know when load is changing i think because it does some fine tuning differences with fuelling depending on if you suddenly step on accelerator etc? dont know exactly how the ECU uses this.*
Expected values: around 0.4v when closed, around 4-5v when fully open."

 

check your o2 sensor is working, see if it swings the full range. If it doesn't and stays on 00.2 it might be fried, that could be an issue. Not sure if that would create lean conditions and retard the timing? 

Maybe go for a drive make a ecutalk log and upload it.

 

[dtrants]

Thanks dyl33! Thats some great info there. Appreciate you digging all that up. Very helpful.

 

dtrants