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Simon86

Need help with cold start and closed loop driving and idle afr's

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Hi guys,

 

I am wondering if there would be someone willing to help me with my current tune.

Cold start is not the best and also noticing it runs too rich on first start up and sits at 10.0 AFR then slowly increases. 

Also noticing when you tap the accelerator it will idle hunt afterwards.

 

I need to adjust some stuff in the closed loop driving.

 

I am also wondering with E85 what should be my idle target at 1,000 RPM ? 14.7 AFR (1.000 Lambda) or more closer to 13.2 AFR (0.9000 Lambda)

 

Car is a 2005 STi with a built 2.6L engine running a Fp red turbo and all the supporting mods.

 

Thanks for any feedback or recommendations in advance. 

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For your cold start use the Warm Up Enrichment table.

Get your Lambda where the car is happiest at warm idle somewhere between .9 and 1.0

Start the car cold and follow it through the Warm up Enrichment table adjusting the values to suit whatever the car likes. Don't be set on a number. It may want to be richer than .9 on it way up in temperature. It will take more than one cold start to get it really nice.

That is a start point. I found to get it real nice it is a combination IAC control and Lambda over a period of time.

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Hi Rob,

 

Thanks for the reply.

 

I have attached the current map as well as a example of the cold start idle hunt.

 

Any ideas?

 

Thanks for  any suggestions 

On 3/15/2019 at 6:16 AM, Rob W said:

For your cold start use the Warm Up Enrichment table.

Get your Lambda where the car is happiest at warm idle somewhere between .9 and 1.0

Start the car cold and follow it through the Warm up Enrichment table adjusting the values to suit whatever the car likes. Don't be set on a number. It may want to be richer than .9 on it way up in temperature. It will take more than one cold start to get it really nice.

That is a start point. I found to get it real nice it is a combination IAC control and Lambda over a period of time.

 

 

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Couple of things you can change to get it a lot better, then grab another log if its still not right

1) Disable VVT around your idle RPM by either upping the lockout RPM on your VVT to say 2k or, change the VVT target table so it has 0 target at 2k below 30% or add in another column at ~1800 and set this to 0 below 30%tps. This is because you VVT is advancing by 10deg or so as soon as you get above idle rpm and throwing things off

2) as suggested by RobW, change idle control to open loop with the engine dead cold, then let it warm up and as it hits the center of each cell in the idle base position table. In general, your table values are about 45 and closed loop is running the idle valve at about 55 to keep the idle rpm you want. If your open loop table values were much closer to what your engine actually wants it will be depending less on closed loop control to keep stable.

3) its going very lean (1.2 lambda) at a couple points around idle. setting the fuel table value for 1500 @ -60 MGP and the same row @ 1000 rpm about 5-10 points higher might help as well.

Once you have it approximately stable, try to smooth out the ignition table around idle rpm, and once its about right, turn on idle ignition control which will help keep idle stable - you just shouldnt use it to fix idle that is otherwise all over the show.

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58 minutes ago, cj said:

Couple of things you can change to get it a lot better, then grab another log if its still not right

1) Disable VVT around your idle RPM by either upping the lockout RPM on your VVT to say 2k or, change the VVT target table so it has 0 target at 2k below 30% or add in another column at ~1800 and set this to 0 below 30%tps. This is because you VVT is advancing by 10deg or so as soon as you get above idle rpm and throwing things off

2) as suggested by RobW, change idle control to open loop with the engine dead cold, then let it warm up and as it hits the center of each cell in the idle base position table. In general, your table values are about 45 and closed loop is running the idle valve at about 55 to keep the idle rpm you want. If your open loop table values were much closer to what your engine actually wants it will be depending less on closed loop control to keep stable.

3) its going very lean (1.2 lambda) at a couple points around idle. setting the fuel table value for 1500 @ -60 MGP and the same row @ 1000 rpm about 5-10 points higher might help as well.

Once you have it approximately stable, try to smooth out the ignition table around idle rpm, and once its about right, turn on idle ignition control which will help keep idle stable - you just shouldnt use it to fix idle that is otherwise all over the show.

Cj,

 

Thank you for your inputs also :) I will adjust my map and see if I can get this sorted.

 

Once again thank you. 

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Hi gents,

So I had a bit of a play and I have adjusted a few things as mentioned above.

 

Played with the fuel trims

Disabled VVT around the idle RPM by upping the lockout to 2,000 RPM

Changed idle control to open loop

I played with the idle base position tables (let me know if this seems right)

 

Also the idle hunt seems to have gone with the higher RPM lockout.

 

My other question is do my AFR'S look like they are going too rich when i tap the accelerator when the REVS come down? You can see this in my second log 2of2 i believe. 

 

Once again thanks for any recommendations. It is greatly appreciated.

 

Thanks,  Simon 

 

Cold start revision 1.2 1of 2.llg Cold start revision 1.2 2of2.llg Revision 1.2.pclr

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I usually run idle in open loop first to set the idle positions(solenoid).

The warmup fuel will be set at the same time.

Idle ignition then turned on and set.

Finally, Idle will be set to close loop to test.

Before you tackle the blipping, make sure that you have Fuel table tuned for load sites you would be visiting.

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The problem is I am not tune minded and I am learning as I go. I understand alot but I have never put it to practice so to speak. 

 

This car was tuned by a local and as you can see it is not 100%

 

I do not trust or do I have two hours to commute there and back each time. 

 

There car has been there 5 times after the initial tune and I just don't have time or patience to waste on this so called tuner. I rather do this slowly but surely and learn something on the way. 

 

Once again thank you. 

 

Cheers, Simon 

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