i guess if i removed the newbie part of the title i might get more responses? 
newbie tuner question closed loop vs open loop)
newbie tuner question closed loop vs open loop) could someone please help me figure this out. I cant seem to grasp the idea or im reading it wrong.
WAt are the typical afflictions when running in either of the two?
Thansk in advance!!
Angel
WAt are the typical afflictions when running in either of the two?
Thansk in advance!!
Angel
open loop - cold start up, hot start for the first 30 second(not sure on how long) and wot.
closed loop - normal cruising
closed loop - normal cruising
Last edited by Checkmate; May 16, 2005 at 10:37 AM.
What exactly is the question??
CL= 'Normal' operation where the ECU uses feedback from the stock NBO2 sensors to keep the car at the prescribed AFR (typically 14.7:1 for non WOT operation). Done primarily for fuel effiecieny as well as part throttle drivability to an extent.
OL= The NBO2 sensors are essentially 'ignored' by the PCM, instead relying soldey on the fuel maps/tables stored in the PCM's memory to fuel the engine per rpm/load. At least that's how OL works on Honda-based ECU's, from what little I understand of LS1/GM systems, when at WOT (PE mode) the PCM will use monitored LTFT's to make adjustments to the fueling in PE mode as opposed to strictly fuel off the map (or maps in the case of the GM PCM's). I'm not 100% sure about that though so I wouldn't take my word for it.
CL= 'Normal' operation where the ECU uses feedback from the stock NBO2 sensors to keep the car at the prescribed AFR (typically 14.7:1 for non WOT operation). Done primarily for fuel effiecieny as well as part throttle drivability to an extent.
OL= The NBO2 sensors are essentially 'ignored' by the PCM, instead relying soldey on the fuel maps/tables stored in the PCM's memory to fuel the engine per rpm/load. At least that's how OL works on Honda-based ECU's, from what little I understand of LS1/GM systems, when at WOT (PE mode) the PCM will use monitored LTFT's to make adjustments to the fueling in PE mode as opposed to strictly fuel off the map (or maps in the case of the GM PCM's). I'm not 100% sure about that though so I wouldn't take my word for it.
no, basically that was my question. I just needed to understand the difference betweent eh the two and more importantly, wat they meant be "make sure its in closed loop" or "or are you sure your in close loop?"
Is there an enable key that dictates which loop your in or is it by a table and its values?
Also, here is another thing i would like help in:
Whenever i turn on the a/c, the temp goes up to over 238-245*....i know it should run hotter but this is to much!!! Is there anything i can do with the hp tuner to make this not happen. THe temp sensor is farily new and im gona adj. the fan-on temps to see wat happens...is there anything i should look for?
Is there an enable key that dictates which loop your in or is it by a table and its values?
Also, here is another thing i would like help in:
Whenever i turn on the a/c, the temp goes up to over 238-245*....i know it should run hotter but this is to much!!! Is there anything i can do with the hp tuner to make this not happen. THe temp sensor is farily new and im gona adj. the fan-on temps to see wat happens...is there anything i should look for?
Originally Posted by obZidian
Is there an enable key that dictates which loop your in or is it by a table and its values?
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Verdad Gallardo Just briefly flipping through the screens here on Tunercat, I see a 'Closed Loop Enable Coolant Temp. Threshold vs. IAT' map that calls my attention. Apparantly you can simply change the coolant temp value at which the PCM switches to CL, simply raise it to a level the coolant will never actually reach and viola! Permanent OL.
Now I don't know if this is the 'status quo' way of disabling CL on GM's, like I said it's just something I stumbled accross here while going through the maps.. I've got ALOT to learn!! Sometimes I miss Honda maps with there grand total of 4 maps vs. the 40+ on these GM's!!
Now I don't know if this is the 'status quo' way of disabling CL on GM's, like I said it's just something I stumbled accross here while going through the maps.. I've got ALOT to learn!! Sometimes I miss Honda maps with there grand total of 4 maps vs. the 40+ on these GM's!!
