Is MAF used AT ALL in open-loop?
07-18-2005, 06:53 PM
#1
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Is MAF used AT ALL in open-loop? I've ready a few other threads about start-up issues, etc, and dealing with correcting the primary VE table. My question is this, in open loop mode (both cold and WOT) does the MAF do anything at all???
As a secondary question, in closed-loop, does the VE table do anything at all??
Thanks,
Dave
As a secondary question, in closed-loop, does the VE table do anything at all??
Thanks,
Dave
07-18-2005, 07:53 PM
#2
Yes, maf is used during open loop.
It is not so much maf = open and closed = VE as the 2 are unreleated. Open closed loop only effects if the o2 sensors are providing feedback.
Ve is used for transient fueling for both open and closed loop. Attached is a link that is helpful.
http://www.efilive.com/forum/viewtop...f693ae78947460
Ryan
It is not so much maf = open and closed = VE as the 2 are unreleated. Open closed loop only effects if the o2 sensors are providing feedback.
Ve is used for transient fueling for both open and closed loop. Attached is a link that is helpful.
http://www.efilive.com/forum/viewtop...f693ae78947460
Ryan
07-18-2005, 10:35 PM
#3
Hi Dave!
Open Loop as stated by Slow -> No O2 sensor input to PCM.
Closed Loop -> O2 sensor input to PCM.
MAFless - MAF sensor not present or inoperable No MAF input to PCM
MAFless tune (aka Speed Density or SD) can be either Open or Closed loop operation.
MAF tune ( operational MAF sensor) can be either Open or Closed loop operation.
VE table is critical both Open and Closed Loop. VE is used to calculate all injector pulsewidths.
I put the GA cam in my Z06 and it ran like crap below 3000 RPM (10:1 afr at idle!) until I recalculated a new VE table - over 2 years ago. It's much easier to do now with EFILive FlashScan.
Are you guys able to run MAFless in the WC GT series?
Open Loop as stated by Slow -> No O2 sensor input to PCM.
Closed Loop -> O2 sensor input to PCM.
MAFless - MAF sensor not present or inoperable No MAF input to PCM
MAFless tune (aka Speed Density or SD) can be either Open or Closed loop operation.
MAF tune ( operational MAF sensor) can be either Open or Closed loop operation.
VE table is critical both Open and Closed Loop. VE is used to calculate all injector pulsewidths.
I put the GA cam in my Z06 and it ran like crap below 3000 RPM (10:1 afr at idle!) until I recalculated a new VE table - over 2 years ago. It's much easier to do now with EFILive FlashScan.
Are you guys able to run MAFless in the WC GT series?
Last edited by Bink; 07-18-2005 at 10:40 PM.
07-19-2005, 07:15 AM
#4
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thanks, it just seems redundant that it needs both at the same time.
Yes, we are allowed to run MAFless, but I haven't gotten it running well with a MAF yet.
Since the car is not street legal, and we never run at low speeds, it is impossible to run it long enough to get ltrims. I guess I should just unplug the MAF and tune the VE table based on wide-band O2 until I get it close, then fine tune the PE table.
Yes, we are allowed to run MAFless, but I haven't gotten it running well with a MAF yet.
Since the car is not street legal, and we never run at low speeds, it is impossible to run it long enough to get ltrims. I guess I should just unplug the MAF and tune the VE table based on wide-band O2 until I get it close, then fine tune the PE table.
07-19-2005, 07:45 AM
#5
Originally Posted by Dave F
thanks, it just seems redundant that it needs both at the same time.
Yes, we are allowed to run MAFless, but I haven't gotten it running well with a MAF yet.
Since the car is not street legal, and we never run at low speeds, it is impossible to run it long enough to get ltrims. I guess I should just unplug the MAF and tune the VE table based on wide-band O2 until I get it close, then fine tune the PE table.
Yes, we are allowed to run MAFless, but I haven't gotten it running well with a MAF yet.
Since the car is not street legal, and we never run at low speeds, it is impossible to run it long enough to get ltrims. I guess I should just unplug the MAF and tune the VE table based on wide-band O2 until I get it close, then fine tune the PE table.
07-20-2005, 06:11 PM
#7
Originally Posted by Dave F
my system is wired to run either an external IAT or the one in the early MAF, so I'm covered. Thanks for the reminder.
Dave
Dave
