ECM Constants
08-27-2003, 11:28 PM
#16
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Originally posted by anaik
Good info for someone new to tuning, like me. I do have a correction, the stock LT1 stat is 180*. The LS1 is 195*
Good info for someone new to tuning, like me. I do have a correction, the stock LT1 stat is 180*. The LS1 is 195*
EvilZ28...
Excellent info on the Low PRNDL stuff. I'll add that to it.
That's the kind of stuff I'm looking for. Thanks.
08-27-2003, 11:34 PM
#17
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Location: Lockport, Illinois 60441
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No prob. I will learn more as I tune my one Trans am. Just taking it slow. Still breaking in the new motor so dont want to go ballistic with programming till she's broken in. This is my GO TO sheet when I am not sure on something. I appreciate this post! 
03-08-2004, 09:44 AM
#18
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Fuel cutoff speed: This is what initiates your speed limiter.
Most set this to the highest speed possible (255 mph) to prevent a speed limiter from kicking in.
Fuel resume speed: Opposite of above...most set it 1 mph lower than the the cutoff.
Fuel Cutoff, 1st gear: This is an rpm limiter that initiates fuel cut off when the specified RPM is reached. Stock is set to approx. 5800. Set the value a few hundred RPM higher than your desired shift.
Fuel Cutoff, 2nd- 6th: Same as above cutoff, just for all other gears. Normal procedure is to set it that same as the 1st gear cutoff.
Fuel Resume, 1st Gear: This matches up with the cutoff and again you should set the Resume value a little lower than the cutoff value.
Fuel Resume, 2nd-6thgear: This matches up with the cutoff and again you should set the Resume value a little lower than the cutoff value.
Most set this to the highest speed possible (255 mph) to prevent a speed limiter from kicking in.
Fuel resume speed: Opposite of above...most set it 1 mph lower than the the cutoff.
Fuel Cutoff, 1st gear: This is an rpm limiter that initiates fuel cut off when the specified RPM is reached. Stock is set to approx. 5800. Set the value a few hundred RPM higher than your desired shift.
Fuel Cutoff, 2nd- 6th: Same as above cutoff, just for all other gears. Normal procedure is to set it that same as the 1st gear cutoff.
Fuel Resume, 1st Gear: This matches up with the cutoff and again you should set the Resume value a little lower than the cutoff value.
Fuel Resume, 2nd-6thgear: This matches up with the cutoff and again you should set the Resume value a little lower than the cutoff value.
03-08-2004, 11:10 PM
#20
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Botch,
Pretty sure I remember seeing that formula that I gave in a couple of threads on this forum. I've used it with pretty good luck so far.
Could be wrong though.
I've also edited the initial post.
Pretty sure I remember seeing that formula that I gave in a couple of threads on this forum. I've used it with pretty good luck so far.
Could be wrong though.
I've also edited the initial post.
10-27-2005, 08:14 PM
#23
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re: ECM Constants
ok, heres one, for Datamaster, while looking at the FUEL TRIM CELL which is normally 16 at idle...
What is this, and how do I tweek it in Tunercat? Is this what is causing my car to run rich at idle? Hotcam
What is this, and how do I tweek it in Tunercat? Is this what is causing my car to run rich at idle? Hotcam
10-30-2005, 06:23 PM
#25
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re: ECM Constants
I believe that biases the intire spark table what ever degree you put there.
For instance, you put in a 2, then that would advance the entire timing curve 2 degrees.
I think of it as turning the distributor on and older motor. The difference would be that it would not advance past the MAXIMUM SPARK ADVANCE constant.
For instance, you put in a 2, then that would advance the entire timing curve 2 degrees.
I think of it as turning the distributor on and older motor. The difference would be that it would not advance past the MAXIMUM SPARK ADVANCE constant.
03-08-2006, 02:56 PM
#27
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re: ECM Constants
Which begs another question asked in another thread...
What is the actual formula(s) used to determine the Pulse-width of fuel and Timing. These are the only real tunable factors to resolve.
IAT, RPM, Coolant Temp, Throttle Position, MAF, IAC steps, BLMs, 02, closed/open loop, WOT table, Ve table, spark advance, etc., etc.
What is the actual formula(s) used to determine the Pulse-width of fuel and Timing. These are the only real tunable factors to resolve.
IAT, RPM, Coolant Temp, Throttle Position, MAF, IAC steps, BLMs, 02, closed/open loop, WOT table, Ve table, spark advance, etc., etc.
03-08-2006, 03:55 PM
#28
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re: ECM Constants
Originally Posted by wwarnke
ok, heres one, for Datamaster, while looking at the FUEL TRIM CELL which is normally 16 at idle...
What is this, and how do I tweek it in Tunercat? Is this what is causing my car to run rich at idle? Hotcam
What is this, and how do I tweek it in Tunercat? Is this what is causing my car to run rich at idle? Hotcam
You can change the RPM and MAP limits for the cells, but you can't change their "number". This is just the identifier for the register that stores the left and right bank long term fuel corrections used for operating under that particular combination of RPM and MAP.
The numbers stored in the Cells don't cause it to run rich..... that is simply the PCM's learned response to a perceived rich or lean condition. Of course if the feedback from the O2 sensors is corrupt, the long term corrections can cause it to run rich or lean.
03-08-2006, 04:01 PM
#29
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re: ECM Constants
This forum is moderated by Andrew of AKMCables. He doesn't seem to be posting much lately, although he did put a post in "Classic Car Tech" yesterday.
This isn't my forum, but I can sticky things.... I'll give it a try, recognizing that it's Andrew's forum and he might not agree.
This isn't my forum, but I can sticky things.... I'll give it a try, recognizing that it's Andrew's forum and he might not agree.
03-08-2006, 07:51 PM
#30
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re: ECM Constants
I have noticed during tuning a MAF car that changes to the VE tables don't really seem to make a difference at all to the way the car runs.
Is the VE table just a backup incase the MAF sensor dies?
If you unplug the MAF will it default to speed density mode so you can tune the VE tables?
Also, here's one for yall. I work on boiler and turbine controls for a living, so, naturally, I get into car tuning as well. ANyhow, at work i have an O2 probe that reads O2 in percent from 0 to 20.8 (atmosphere) accurately. I pulled the thing apart once after it failed and noticed that the sensor in the end of the probe was a FORD part number. I called the company, Bailey Controls, that manufactured the probe and analyzer. THey wanted like 200 bucks for the O2 sensor. Then I called Autozone and crossed the part number and only paid 95 bucks for the sensor.
Question. are all automotive grade O2 sensors interchangeable except for the plug?
What I am getting at, can we buy two, dare I say it, FORD O2 sensors, put them into our FBodies and BAM....wide band O2 reading for us home tuners?
Is the VE table just a backup incase the MAF sensor dies?
If you unplug the MAF will it default to speed density mode so you can tune the VE tables?
Also, here's one for yall. I work on boiler and turbine controls for a living, so, naturally, I get into car tuning as well. ANyhow, at work i have an O2 probe that reads O2 in percent from 0 to 20.8 (atmosphere) accurately. I pulled the thing apart once after it failed and noticed that the sensor in the end of the probe was a FORD part number. I called the company, Bailey Controls, that manufactured the probe and analyzer. THey wanted like 200 bucks for the O2 sensor. Then I called Autozone and crossed the part number and only paid 95 bucks for the sensor.
Question. are all automotive grade O2 sensors interchangeable except for the plug?
What I am getting at, can we buy two, dare I say it, FORD O2 sensors, put them into our FBodies and BAM....wide band O2 reading for us home tuners?
