Rich at idle

[Goody_Seven]

Car is a 382 LS1 8.85Cr with a turbo and stock cam 60lb injectors. I can get the A/f perfect at everywhere I want it, but nothing I change effects idle (10.1 A/f). What values do I need to change to get idle to lean out? Also it is creating some hard start problems. On a side note the second you open the throttle the A/f goes where it needs to be, but when the throttle is at 0% the car gets extremely fat (8.9 A/f on decel) Thanks

[killer01ws6]

Need to take some fuel out in the VE table...

400 X .60
800 X .80
1200 X .90
only down to 55KPA

[disasm]

I am helping Goody_Seven with this tune...

Basically we can get the car to be as rich as we want, but in the places where we need it leaner we can't make it work. For instance - with the VE table set to 0 from 0 - 55kPa all the way up to 1600 rpm and it was still 10.9 air/fuel ratio on the wide band. Tried this on both primary and secondary VE tables.

Is there some other table that we need to adjust to make this car idle properly? Or is there some kind of minimum injector duty cycle value that needs to be adjusted for these 60lb/hr injectors?

Any help is appreciated...

[killer01ws6]

Well I have not done what you guys are trying...
but I do know if you have a car that has 2 tables you do all of the adjusting with the secondary,

and for the injectors you want them set for the proper flow first before you do the rest.

if not you are kinda going in circles

[disasm]

Well I have not done what you guys are trying...
but I do know if you have a car that has 2 tables you do all of the adjusting with the secondary,

Well I assume that this car has 2 tables because I can click on both the primary and the secondary VE buttons.

If all the adjusting is done with the secondary table then what is the primary table used for?

[Goody_Seven]

I swear we moved every single table and nothing changed, I could make idle A/f worse, but not better.

[disasm]

I swear we moved every single table and nothing changed, I could make idle A/f worse, but not better.

Ok guys, is it impossible to tune idle air/fuel ratio with HP Tuners or what? We have tried everything from the injector flow rate table to speed density tuning to MAF frequency changes to dropping the VE to zero. Nothing works to lean out idle. OTOH we can very easily make idle go from 10.6 A/F (where it is now) to deep into the 9.0's.

Very frustrated...

[disasm]

Here's some more info about this problem.

I seems that when we make changes to any of the tables that those changes do work, EXCEPT at idle and/or closed throttle. For instance it will run 10.6 A/F at idle and if we blip the throttle it will go 14.6 until the throttle is closed and it goes back to idle, then it goes back into the 10's. When cruising down the road it has perfect A/F until you close the throttle and it starts to decel then it goes pig rich again. So I'm not sure if this problem is an idle problem, or a closed throttle problem, or what.

Any help is appreciated...

[Billiumss]

Car is a 382 LS1 8.85Cr with a turbo and stock cam 60lb injectors. I can get the A/f perfect at everywhere I want it, but nothing I change effects idle (10.1 A/f). What values do I need to change to get idle to lean out? Also it is creating some hard start problems. On a side note the second you open the throttle the A/f goes where it needs to be, but when the throttle is at 0% the car gets extremely fat (8.9 A/f on decel) Thanks

My guess is that your injectors are the problem. You might have to adjust the Injector offset voltage.

[killer01ws6]

That will move all of your adjustments also....

so you sweetspots will need to be readjusted.

[disasm]

What is the injector offset voltage table measured in? Milliseconds? And what is the best way to go about adjusting it? Maybe just start by multiplying everything by 0.5?

[killer01ws6]

What is the injector offset voltage table measured in? Milliseconds? And what is the best way to go about adjusting it? Maybe just start by multiplying everything by 0.5?

I would get the "factory" specs for the injectors you have now, and set the table to be correct.

I am sure that where you got them or some paper work should have the correct flow information.

[disasm]

The injectors that are being used on this car are the Mototron (Siemens Deka) 60lb/hr injectors. They are said to flow 6.9-10.7 g/S @ 250-600 kPa. But how do I convert this to injector offset voltage?

[Rapture]

I've just started with HP Tuners, but reading the help file it says the following:


Changing Injectors


Location: Edit->Engine (Fuel Control Tab)->General Fuel Section->Flow Rate vs. KPA Table
Open up the Unit Conversion window found under the Tools menu.
In the lower right, enter in your new injector flow rating and the fuel pressure it is rated at.
Then enter in the fuel pressure of your fuel rail.
Your new injector flow rate will be calculated automatically. This rating is for 0 VAC.
As manifold vacuum increases the injector flow rate will slightly increase.

If I'm reading correctly, the injector voltage offset mentioned here must refer to, as stated in "Help," the following:

Injector Offset vs. Battery Voltage vs. KPA Vac: This value is added to the injector pulse width as the delay time it takes for the injector to operate. It varies with battery voltage and manifold vacuum.

It would appear that you use the conversion tool to determine what your flow should be for your new injectors based on your current fuel pressure. Once you know your fuel rail pressure, input the values into the conversion calculator as follows (use either the low or high values for your injectors....you'll get close to the same number). 1.) Convert your flow to lbs/hr using the tool (e.g. 6.9 g/s = 54.76 lbs/hr). 2.) input that value in the lower right for your "Current INJ Flow" 3.) calculate your pressure in psi from kPa (Must match the flow rate value you input, e.g., 250 kPa = 36.26 psi) 4.) input that value in "Current Fuel Pressure" 5.) input the car's actual fuel rail pressure in the "New Fuel Pressure" window. 6.) your answer should appear in the last window.

Now, with the new value you're gonna have to go to the "Flow Rate vs. KPA" tab under "General Fuel" and make adjustments correspondingly. Since you already adjusted everything according to the "incorrect" values for Flow Rate vs. KPA, you'll have to restart your tuning. However, this should, I would think, allow you to adjust your idle enrichment now.

Remember, however, this information is provided based on the help files and logic only.....no experience. But this might at least get you headed in the right direction.

[WS6snake-eater]

Just realized the car is a 382. You did change the cylinder volume right?

[disasm]

Yep, that was among the first things that were changed.

[eatme]

I have the same injectors and I also experience the same exact thing. I've been trying to figure this out for months. If anybody has any "inside" information, please share it with us.

[Goody_Seven]

One thing I notice is that the min injector pulse width doesn't go lower than 1.8ms with changes. If I set the offset voltage low enough the car will run at 14.* at idle, but has some lean misfires and wants to die all of the time at idle. Is there just no solution to this???

[FRC_Tom]

Try the airflow vs. tps table if you have already changed the Idle Airflow vs. Coolant Temp vs. Gear/P/N.

[Holty]

Goody_Seven, did you ever figure this out? what was your solution?