Under VCM controls for Fuel & Spark my Fuel Trim buttons are grayed out, is this option not available?
I'm using hpt 2.1.10 on a 2001 cavalier 2.4l
Under VCM controls for Fuel & Spark my Fuel Trim buttons are grayed out, is this option not available?
I'm using hpt 2.1.10 on a 2001 cavalier 2.4l
I have the same problem on my 2.2L ecotec 2003 cav.
If it's greyed out it is not available. *But* you must be scanning for the VCM controls to work initially.
EC
Always Support Our Troops!
I can get the controls to work it's just that I wasn't sure if their was some kind of upgrade I needed to gain control over the fuel trims. I've read ypu can adjust the trims with VE tuning. But, some suggest to start with spark advance and thats where I am totally lost.
You need to tune both. I would start with VE tuning and adjust spark as necessary (if you see excessive knock).
EC
Always Support Our Troops!
So do I keep increasing the VE until I get excessive knock then adjust spark? A little help on how to scan properly and set up the histograms would go a long way for me. I keep looking on the forum but most of it relates to V8's and cars with maf as well as other options my junker doesn't have.
You should be logging LTFT vs MAP vs RPM in a histogram. When you are done logging you will see + and/or - values of LTFT. Copy the Histogram table & paste it into your VE table using Paste - Special Multiply %. It's really that simple... You may have to rinse & repeat a few times to get it well dialed in.
Make sure you reset fuel trims after programming.
Happy tuning!
EC
Always Support Our Troops!
awesome thanx for the support. I have to give it a shot sometime this week.
2003 Cavalier 2.2 L4. Modified Intake and throttle body. Header and 2000 watts of boost in the trunk.
On my histo I used LTFT as plot value and x/y header as main spark vs MAP vs RPM High Octane. is this correct ? But you said to paste into the ve table which is TPS vs RPM. Did you actually mean the spark tables? When I tried to paste into the spark table it gave me an error. I can't find any paste special like you mentioned. Am I on the right track? should I just edit the spark table one cell at a time?
2003 Cavalier 2.2 L4. Modified Intake and throttle body. Header and 2000 watts of boost in the trunk.
The LTFT plots in the map vs RPM are for VE tuning..not spark tuning. The plot values from the LTFT histo is copied and pasted, using paste special [usually with multiply by half]. Program it in, clear the fuel trims, drive and log again until you get where you want to be.
Edit...You are saying the VE tables are in TPS vs RPM....can you post a log and the current tune you have...see what you have going on here. I cant promise I can answer the questions, but it would help out someone else who could.
Last edited by toyoguru; 07-19-2006 at 07:55 PM.
here is the files for a stock edit and log. Also I can't reset fuel trims as I said earlier. There is very little I can do with the VCM controls.
2003 Cavalier 2.2 L4. Modified Intake and throttle body. Header and 2000 watts of boost in the trunk.
do we have to set into speed density to do this or can we just log it and change it untill it works?Originally Posted by EC_Tune
also should this be done before or after we change the ve to compensate for larger injectors that the ifr table cant?
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