Poor Cold Idle (Yes I searched) - Page 2

Appauldd · Oct 10, 2009, 12:02 PM

Quote:

Originally Posted by EVOIXreno

Sometimes the trims might be ok but that doesn't mean they are scaled correctly.

Then how would one test fo accuracy in injector scaling? My car will idle, when warm, at exactly 14.7 AFR with these trims.

biggie5252 · Oct 10, 2009, 01:48 PM

There's a thread around here about disabling the egr bit (i think its faa bit 11) and cold idle. If you log it you will see that it switches over at 154.4*F then it will idle fine.

Appauldd · Oct 10, 2009, 03:45 PM

I realize it idles fine once it warms up. I want to find the table that causes the condition in the first place.

Fast_Freddie · Oct 10, 2009, 03:53 PM

I have had the same problems also either with faa bit 11, or with the new EGR disable routine... both have the same effect on old start warm up... I just see it as a "feature" now...

biggie5252 · Oct 10, 2009, 06:38 PM

Quote:

Originally Posted by Appauldd

I realize it idles fine once it warms up. I want to find the table that causes the condition in the first place.

Disabling bit 11 causes the condition (I'm sure you already know this). I don't think anyone has found a table that will fix it though, with the bit disabled. I know I went through every table in ecuflash trying to fix it to no avail, until I reenabled the bit and it worked.

Appauldd · Oct 10, 2009, 08:49 PM

So how can we remove the EGR and still have good cold idle ? ?

Fast_Freddie · Oct 10, 2009, 09:24 PM

Also just did some logging and I am getting a rich start condition when the car is warm also... it idles at 13.1 until the coolant temp comes back up to 199.4* then you can see inector pulse width and duty cycle drop and it idles perfect at 14.7....

biggie5252 · Oct 10, 2009, 10:23 PM

Quote:

Originally Posted by Fast_Freddie

Also just did some logging and I am getting a rich start condition when the car is warm also... it idles at 13.1 until the coolant temp comes back up to 199.4* then you can see inector pulse width and duty cycle drop and it idles perfect at 14.7....

What coolant temp are you logging? I logged coolant temp scaled (evoscan) and it was always at 154.4*. The second it hit that my rpm jumped up for a second, settled out, and then the car idled perfectly from then on. Even if I did a warm start and coolant temp was less than that it idled crappy until it heated back up past it. Although it did seem to get progressively better as it warmed up.

Fast_Freddie · Oct 11, 2009, 01:57 AM

Quote:

Originally Posted by biggie5252

What coolant temp are you logging? I logged coolant temp scaled (evoscan) and it was always at 154.4*. The second it hit that my rpm jumped up for a second, settled out, and then the car idled perfectly from then on. Even if I did a warm start and coolant temp was less than that it idled crappy until it heated back up past it. Although it did seem to get progressively better as it warmed up.

Unscaled coolant temp... and yes what you explained is exactly what happens. With the V7 rom on the 0006 rom it seems to actually be worse than the 0011 rom...

Appauldd · Oct 11, 2009, 07:29 AM

Quote:

Originally Posted by Fast_Freddie

Unscaled coolant temp... and yes what you explained is exactly what happens. With the V7 rom on the 0006 rom it seems to actually be worse than the 0011 rom...

Thus, my hesitance to switch just yet. It does look promising though.

chrisw · Oct 11, 2009, 08:42 AM

just out of curiosity, have you checked for boost leaks?

Fast_Freddie · Oct 11, 2009, 11:08 AM

^^^Yes... it is all coolant temp based in my assumption... Isn't the ECU in open loop at start up? Then when the temp reaches a certain temperature it goes into closed loop?

biggie5252 · Oct 11, 2009, 12:31 PM

Quote:

Originally Posted by Fast_Freddie

^^^Yes... it is all coolant temp based in my assumption... Isn't the ECU in open loop at start up? Then when the temp reaches a certain temperature it goes into closed loop?

I think it only goes open loop for like 30 seconds or something.

nothere · Oct 11, 2009, 12:40 PM

Quote:

Originally Posted by biggie5252

I think it only goes open loop for like 30 seconds or something.

I just looked at a log and I think I have to agree, the stft kick in about then.

So, that would suggest its a matter of tuning your maf compensation
(scaling). Or possibly your latencies.

fostytou · Oct 11, 2009, 02:02 PM

Quote:

Originally Posted by Appauldd

My injectors are scaled to allow me to have LTFT low of -1.03 and LTFT mid of -0.99. I don't think that they can get any better.

I think there is a table that is used for cold warm up that retards the timing until the cat is warmed.

I had trims for my 1200cc +/-3% before rescaling. Trims are a little better now, and the car drives like a champ. I thought it drove very well before, but now it is amazingly better. Can't hurt to give it a try. To tie this to my next comment, reset your MAF scaling and compensation if you try this. I would highly recommend giving this method a try. I know it can be a little bit of a pain later to get everything *perfect* again, but it can't hurt to try and see if your driveability improves with a couple of flashes.

The other thing to check is if you have scaled your MAF down at all. I think this plays a part in the warm-up fueling also even if it is perfect once warm.

The interesting thing was that when i did this my scaling went to an almost-perfect expected value (~1150*.7(ecuflash scaling)*.7(e85)). I lowered the latencies quite a bit, but you may not need as drastic of a change.
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I also noticed in my case that it was right around a certain coolant temp that it would go from bad to good. Can't remember where off the top of my head though.