Funny problem with idle

[SSpdDmon]

So, I'm running a D1SC with some 60-lbers and a twin in-tank pump setup. There's an adjustable regulator as well.

Anyway, the problem I'm noticing is the car is pig rich at idle when I start it up and drive around....until I go WOT once or twice. Then, the idle straightens right out to stoich.

I think it has to do with the MAP sensor and the PCM trying to learn the atmospheric pressure. Is there any way I can get it to stop doing this? I don't want to have to deal with an 11:1 AFR every time I start the car until I go WOT.

I'm guessing I have to turn B0301~B0306 off? Is this ok to do this?

[nonnieselman]

So, I'm running a D1SC with some 60-lbers and a twin in-tank pump setup. There's an adjustable regulator as well.

Anyway, the problem I'm noticing is the car is pig rich at idle when I start it up and drive around....until I go WOT once or twice. Then, the idle straightens right out to stoich.

I think it has to do with the MAP sensor and the PCM trying to learn the atmospheric pressure. Is there any way I can get it to stop doing this? I don't want to have to deal with an 11:1 AFR every time I start the car until I go WOT.

I'm guessing I have to turn B0301~B0306 off? Is this ok to do this?

Is this a Cold Start? If so it is goin to be rich when you crank it. Not sure about 11.1 tho..

[SSpdDmon]

This is happens the whole time the car is at idle....even when the car starts cold and warms up to operating temps in the 180s~190s. Once I get on it, it leans right out.

[nonnieselman]

Now that is weird.... BUMP for ya...

[SSpdDmon]

Bueller.......Bueller......

<crickets>

[Doc]

Let me check to see if I understand completely...

This is happening in closed loop?

You are commanding stoich?

This is on a LS1 COS?

[SSpdDmon]

Std. 99 M6 Fbody OS

Forced open loop

Idle after start and warmup will read 73~75kPa of vacuum (manvac).

After a WOT run or two, idle will read 80kPa of vacuum.

I believe this is because the PCM thinks I'm below sea level and compensates as much as it can for it. But at startup when the car isn't under boost, it reads a true atmospheric pressure.

I guess ideally, I'd like it to read what it is at startup and ignore the WOT adjustments....and I'm hoping that if I turn off the tables I listed above, the car will do just that.

[SSpdDmon]

Well, guess I'll recal the WBO2 this weekend and do a little experimentation...

[zapp168]

Is the valve on the Procharger sticking open a little at idle allowing airflow from it? The air flow would cause it to go rich, then you boost it and it snaps shut harder. I am running a D1SC and 60#'s and of all my issues I do have, that is not one of them. I am running C03 SD OL 2 bar though.

[SSpdDmon]

Is the valve on the Procharger sticking open a little at idle allowing airflow from it? The air flow would cause it to go rich, then you boost it and it snaps shut harder. I am running a D1SC and 60#'s and of all my issues I do have, that is not one of them. I am running C03 SD OL 2 bar though.
The valve has nothing to do with the AFR as it's plumbed into the charge piping a good 4~5 feet before the MAF. I started playing with the Baro update feature and I'm still trying to figure out how exactly it's affecting the car. It might be the key here (with me still being on the stock OS). We'll see....

[zapp168]

I'm Sorry, I meant sticking closed, not opening at idle to bleed off the airflow from the charger, causing more airflow at idle.

[zapp168]

You know ALOT more about this than me, but if your OS is stock why would this be an issue on your car and not other cars? The procharger should make no difference at idle (if the valve is working), and as for the 60's, adjusting the min pulse width and the IFR seemed to be the two main things I needed to do. I try to screw around as little as possible....LOL. I adjusted the baro preasure when I went 2 bar, but that was the only time I touched that. Trying to help and learn at the same time.

[SSpdDmon]

The other thing I'm thinking it might be is the adj. FPR that was installed. Either way, I'm stumped. Since I didn't make much headway this weekend, I think I'm just going to leave it as is and just have to go WOT when I drive it to get the idle AFR's in line. LOL