M6 MPS cold start high revving

[moggies]

Hi all,

New to this tuning and I have installed the Base 91US/95EU Octane tune to my Mazda 6 MPS to try and get better
drivability, as the installed mapping was incredibly aggressive. No way of knowing if it was standard or not, but the base tune
has calmed it down.

I'm looking to reduce the start up revs if possible, as currently its too fast and noisy. 1750rpm on a cold engine cant be a good idea,
plus it does nothing for keeping the neighbours happy.

I have set the idle speeds on the map software but it still races away on cold start.

Can anyone please help?

Thanks

[mituc]

When you start it keep your foot on the acceleration pedal just a bit (like 1/4). If you do this it will start at 1250rpm instead of 1750.

[moggies]

OK thanks, I'll try that. Bit odd as I've lowered the cold start idle on the map?

[mituc]

OK thanks, I'll try that. Bit odd as I've lowered the cold start idle on the map?

During certain situations the engine will use some values in tables I don't think we have access to or are hardcoded in the engine management software, while with these tables we're only changing the calibration/values that works with.
I think this is one of them, the commanded AFR during idle being another one (even if we cna alter the AFRs for that engine speed and load), front radiator fans duty cycle, and so on.

[moggies]

Ok, this cold start revving is definitely worse with the cold weather, but the rpm appears to lower quicker, if the vehicle is started
without pressing the clutch.

I would also like to lean off the mixture without getting too deep into settings, so is there anything basic I can tweak without effecting anything else?

Thanks

[mituc]

Ok, this cold start revving is definitely worse with the cold weather, but the rpm appears to lower quicker, if the vehicle is started without pressing the clutch.

Press the clutch, especially when cold (and gearbox oil is thick)! The only thing you will do is to put more strain on the starter motor, the cold start ECU logic will not actually change. Newer cars with manual transmissions will not even start if you don't press the clutch, and this is for a good reason.

I would also like to lean off the mixture without getting too deep into settings, so is there anything basic I can tweak without effecting anything else?

In what situations you want to lean the mixture and by how much? What do you have in mind?

[moggies]

Just slightly weaken for a bit better economy. The economy map is not that good for general driving so just a tweak on this one.
I'm not interested in thrashing it just a decent drive.

[mituc]

If you want leaner AFRs you may need to disconnect the secondary O2 sensor. Then you will be able to command lambda values above 1 without triggering some failsafe in the ECU which will put the lambda back to 1.
If you still have the cats on I suggest you don't go leaner than 1.03.