Lol, yeah but it's the truth. I've had so many maf equipped turbo cars, that anytime i notice the smallest problem I get out the boost leak tester. I have one in my toolbox in my trunk, you never know when you're going to need it.

 

Eric,

I currently have my latency and injector scaling set to where LTFT and STFT remain within +/-3%. Then I tried to adjust the upper right corner (4-cells) of the open loop fueling map. I chose these 4 blocks since OBDII information reports that I am in 20-26% at this time. My table starts at 15% and jumps by 15% increments. I have changed the values from "14.7" to "12.2". warm up idle does not seem to change. I still seems to start at 13 and migrate up to "15.5" to "16.5" and then back to "13.0" before closed loop kicks in. The problem occurs when the ratio gets above "15.5" and the motor seems to act like it has an ignition miss. This causes the PO300 code and a cr@ppy idle.

I have actually noticed the same with the timing at idle. The open loop timing table does not seem to match either. Are you sure that this has any affect on open loop fueling on warm up cycle?

HiVoltEVO8

 

have you checked your water temp sensor? it may be out of bounds when cold?
perhaps the iat is bad.

shooting in the dark, as it sounds like the fuel cells don't cover "cold" start. trouble as I see it, when it does get cold your car won't idle.

 

You may have to adjust your scaling and latency a bit more.. I spent some time and noticed there are dozens of latency/scaling values that give you a perfect fuel trim, but it takes awhile to find a combination that doesnt load up and still gets the right fueling at higher load..

When I had my injectors scaled larger with higher latency, it ran alot better than when I had latency and size closer to stock.

In open loop your fueling does indeed get controlled by the upper left corner of your fuel table.. I wouldn't rely too heavily on what the load calculations claim since it will get thrown by the closed loop fuel control.

You need to force the car into open loop fueling and adjust it there, since I haven't found (yet) a way to do it with a call to the ECU Only, I wired a switch to the front O2 sensor signal wire, but you can just disconnect it...

Now you can alter the scaling and latency values until you get something that gives you about 14.0 fueling at idle when cold.. If the car won't idle well, alter your timing at idle slightly also.. Now you should get a decent cold start idle and when it runs in closed loop it won't swing wildly either.. If the car is warm, you can go for about 14.5 or so as long as the car idles smoothly.. Now in closed loop it should hover normally and it should start without being so lean..

Another thing to look at is your voltage at idle.. If its 13v or so, look at your 11v latency values and adjust accordingly.. it may be that as your idle speed drops, the voltage drops, and it can start going a little lean..

just a few things to look at.. I am working around something similar, but in my case i'm trying to get my scale and voltage latency to give me AFR's close to what the fuel table actually says in the map...

 

The upper left is what controls open-loop idle, not the upper right. I'm not sure if you mistyped this or not.

Eric

 

I just put a lc-1 in and idle at like 14.3-14.4

When I jump on it in third it richens up to like 11.5/12

 

Uhhhhh, the other right


Yeah, I meant left. It seemed to have no affect

HiVoltEVO8

 

Since you said you only modified "4 cells" I really don't know what your talking about.. but at idle the car dances around all of those cells in the upper left corner.. sometimes it'll be in the 20% column, sometimes it'll be at 90%.. You need to make adjustment to all of the cells in the upper left corner from 0% to 100% from 0rpm to 1250rpm (depending on your axis) wherever your car may idle at..

If your relying on a load calculation to find the cells at idle (or at any time in closed loop) Don't bother, it isn't going to be accurate

Since you say your warm idle is 15.0 or leaner most of the time, I can tell your almost certainly dealing with fuel trims out of range and you need to spend some more time adjusting your injectors..

What size injectors and what is the latency value your using @9v @11v @14v and @16v Remember the ECU interpolates the value, also look at your voltage at idle, it'll fluctuate depending on idle speed (not by much, but it will) if there is a giant numeric difference for 11v and 14v it will affect the flowrate at idle.. Plus the lower voltage makes the injectors lazier..

You would be surprised how many maps I've seen where only the 14v setting was changed and people asked me why their car with 1000cc injectors was so hard to start...

 

Yes, I agree with all of the points MalibuJack has stated. Especially just changing 4 cells to try to control your open loop idle.

Even it is just for a test, take a huge block of the upper left cells, the range described in MailbuJack's post (even higher RPM as the idle will start a bit higher when cold), and change them a few points lower.

For example, if your cells say 14.7, change them to 12.7 or even lower just to see if it does anything....you can always flash it right back. However, it definitely should do something. I'm thinking that you just didn't use the cells that your car may be idling in.

As mentioned, as far as the warm idle, that is a whole other ballgame. That is all about fuel trims and your injectors, from scaling to latencies. But, the fact that your car is having such as hard time idling during the open-loop cold start, it leans towards the fact that your injectors are scaled much too small.


Eric

 

MalibuJack & Eric,

I tried and changed all of the cells ranging from 0-100% and 0-1250 RPM to 12.5. This definately improved the situation. It seems that I was relying on OBDII data to determine that I was in the 15-30% range in load. As Malibu stated, this is being reported incorrectly or at least being deceptive as to which cells you are really occupying.

Thanks for all of the help guys.

HiVoltEVO8

 

Gonna copy and paste soon...

I change my filter element every 10k, needs to be changed soon. I am at 48k right now. Air sensor readings are still good.


First thing done...easiest and cheapest way to solve problems.

No codes thrown for front O2 yet..

I have run a few tanks of 100 UNLEADED at the track and on the dyno...maybe 300 miles worth (4 tanks)

Good idea, thats one good thing to check...

-Vince

 

Anyone else have any suggestions?

-Vince