Cold start issues

[CarloL]

Quick one , I have an M130 but lately after you leave the car sit (24 hrs) , on start up she wants to cut out , 500 rpm on idle or less ; moving her she periodically cuts out

Once warmed up she runs great , if I leave here sit a few hours , no issues

Bit of a strange one , maybe the unusual high weather temps ?

Re calibrate the throttle position sensor on the ECU?

[David Ferguson]

I think posting a logged data file would be the most helpful.

You haven't really provided enough info to allow us to help. It sounds like the tuning could be improved with the compensations (possibly after-start, or the idle-control isn't tuned properly, or the drive-by-wire feed forward table needs help or any of a number of other possible issues.

[Stephen Dean]

As David said, there is a paucity of information provided to assist you, a log file of the issue will greatly assist in the resolution of this issue.

[CarloL]

Log file is 123 mb , but she was trying to stall today when pulling up at traffic lights , clutch in

CAr is a Toyota Supra 2jzgte Manual 6 speed, so nothing fancy tech wise

https://1drv.ms/f/s!Ao-FTTt3GMhrg4Qb72PNqQPeKitomQ

[David Ferguson]

Is your ECU powered by your ignition switch?

The only times I see in the log where the engine stops, it is always running at the idle RPM. It's like the power to the ECU was just switched off. The cold-start where it stops shortly after starting cold appears to be about 642:18 into the log. I don't see any diagnostic conditions, just the same RPM stops immediately while idling.

I would check your ECU power & grounds. Make sure there isn't an intermittent connection there that is affected when starting cold.

I was going to look at the mixture, but you don't seem to have a Lambda Sensor fitted. I can see there is additional fuel being added due to the reduced engine coolant temp, but can't tell if this is enough (or too much) without some lambda data.

I went looking for times when the Idle RPM was low -- I found one at 650:27 -- there I notice the alternator has stopped charging, and the voltage has dropped to less than 12.5.

I was able to load your config into M1 Tune -- and it looks like you have a stepper motor idle control. I wonder if the number of steps are set correctly. Perhaps it "runs out of range" or isn't completely reset when the temps are cold and it needs to open up more. I notice the Idle Mass Flow Feed Forward Main table has the same values for 800 & 900 RPM (and for 800-1000 when 40degC or less. Perhaps those values need to be a bit larger.

If you have logging, perhaps you could log Idle Actuator Stepper, and Idle Actuator Stepper Position.

or if you can be connected with M1 Tune, and be one the page Engine Systems->Idle Actuator -- you might want to change the channels in the Time Graph and see if you can figure out what's going on.

Good Luck.

[CarloL]

Thanks David for taking the time out to review, I owe you a Beer at least

ECU is powered by the ignition switch
LTC & Bosch Lambda sensor is fitted (LTC manager states it is working fine)
Alternator sounds like it is on the way out (Car is a 1993)
She uses the OE Stepper Motor Idle control Valve , 48 teeth from memory


I have logging but not sure how to set it up to log Idle Actuator Stepper, and Idle Actuator Stepper Position.

Will see if I can find a tutorial

[CarloL]

Charged the battery ( Optima Red top)
Car is not used daily , the odd Day , I charged the battery with a Ctek charger ; has helped on initial start ; she has not tried to cut out to date like before

Alternator test
I tested the Alternator with a Volt meter ,

Battery illustrates 12.8 at the battery
Car on , 14.3
Accessaries on , creating a load on the battery 14.3 V

I also updated to the latest Firmware on the LTC , maybe this was not working as I updated the ECU with the latest updates and the LTC need a Firmware to work?

No errors on the ECU , all looks good for that front

LOG

Battery Voltage , min 7.426 was registered in the log ,max 14.32 with an average of 13.369

Most recent Log, the zero drop in the log is when I installed the firmware on the LTC and switch it on/off

https://1drv.ms/f/s!Ao-FTTt3GMhrg4Qb72PNqQPeKitomQ

I am interested , if the LTC is working ; according to LTC manager all is working fine , I can see the Exhaust Lambda Channel in the LOG , Min 14.847 Max : 14.950 Avg: 14.861