AutoVE not working - SOS!

[jamesbond2509]

I am currently usisng COS 03 and trying to Autotune. When I loaded the autove calibration into the PCM the engine would not idle. It chugged smelled liike gas and sputtered. Can anyone help please. I went through the tutorial twice.

Thanks

[Tordne]

Do you have a wide band controller to verify the actual air/fuel mixture? If so what was the actual AFR at idle?

Probably the easiest thing for you to do is attach your tune file to a post here so that w can download and have a look.

[jamesbond2509]

Before downloading the autove file the wideband was reading normal 14.63+/- 0.4. After the calibration file was flashed, the engine could not stay on long enough to get a good wideband readout. It just sputtered.

:nixweiss:

[Tordne]

So.. Prior to attempting the AutoVE were you running with MAF or without (Speed Density)? Could it be that your VE table has been increased too much and it is just super rich? Also check the A0008 table as that is a multiplier to the B3647 fueling table. Generally at operating temps that A0008 table will be a value of 1.0.

[jamesbond2509]

Before removing the MAF was running semi open loop with MAF using the COS.

:nixweiss:

[jamesbond2509]

Also checked A0008 and its set at 1

[dc_justin]

Mind posting up your tune so that we can take a look?

[Tordne]

OK.. I have some findings ;)

First and probably most important the IFR table for your injectors is wrong. In the trucks the IFR table is flat cause they have a fuel pressure regulator (someone had to tell me this a while ago). So I’m guessing that you will need to calculate the values for your stock injectors, the check a stock tune and find out which value they used (0 or 80 kPa vacuum). Then calculate the IFR for your current injectors and then use the value from the 0 or 80 vacuum (whichever you established is correct).

Secondly, I notice that you increased the VE table by probably 15% (think that is what the tutorial calls for). That could be too much.. But, given your mods I’d leave that for the moment and check out the injector stuff first.

Cheers,

[jamesbond2509]

I have disabled the boost reference as the regulator was not reliable. I tried starting up at 10% VE and 15% VE and no luck. Please advise.

Thanks

[TAQuickness]

In the idle region of the VE table, try using stock values or reducing the values just a bit.

[Tordne]

Hey TA, what do you think about the IFR table not being flat on the truck? He says he has disabled the boost reference but I don't know enough about it. I just know that the stock trucks IFR tables are flat, and that if this is the problem he will be over fueling by huge amounts...

[joecar]

Thinking about it...

map-referenced: IFR = R0 * sqrt((FP + BARO) / P0) = constant (e.g. truck)

non-referenced: IFR = R0 * sqrt((FP + BARO - MAP) / P0) = reverse sloped with MAP (e.g. car)

so the map-referenced IFR would be higher than any non-referenced IFR (since MAP never goes to zero);

the higher IFR means the injectors open for a shorter period to deliver the same fuelmass;
so this and the flat IFR means he will be underfueled, especially at high MAP;

Have I gotten it right, or have I mess it up...? :Eyecrazy:

[jamesbond2509]

I tried using a flatlined IFR at 43 (as previous) and no luck! Any other suggestions. Still desparate!

[jamesbond2509]

I went over the tune with Jesse at Wait4me and concluded that either the IFR's need to be adjusted or my VE is way off. so I will try some things over the weekend. If you have any more recommendations please advise.

Thanks!

[Tordne]

So basically what I said then ;) Good luck...

[joecar]

Yep, what Andrew said; IFR is required to be correct otherwise everything else is skewed.

[jamesbond2509]

Andrew and Jocar

Changing the IFR worked!

Thanks for your quick replies!

[Tordne]

Happy to help mate!