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Old 09-17-2010, 06:54 AM   #1
flightwatch
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Default Just noticed something intresting tonight...

When I let off the gas, my car goes into open loop. When I get back on the gas, it goes into closed loop...unless I get on it and then it will switch to open loop. I'm tuned, but I don't remember ever seeing that. Is it normal?
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Last edited by flightwatch; 09-17-2010 at 08:06 AM.
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Old 09-17-2010, 08:01 AM   #2
iluvdrt
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Quote:
Originally Posted by flightwatch View Post
When I let off the gas, my car goes into open loop. When I get back on the gas, it goes into closed loop...unless I get on it and then it will switch to open loop. I'm tuned, but I don't remember every seeing that. Is it normal?
Mine does that until it is warmed up then just stays in open loop all the time.

So in short IDK if it is normal, but mine is wierd too.
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Old 09-17-2010, 09:20 AM   #3
Skidd
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Not sure about the 2006, but it's perfectly normal in my 00RS EJ251.
When you let off the gas, your car cuts all fuel on engine-deceleration.
Thus, your ECU goes into OpenLoop during this "fuel cut" mode.
So yeah, it's normal.
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Old 09-17-2010, 09:28 AM   #4
treksofar
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Mine does the same. Before my tune it would warm up in open loop and tried to remain in CL as much as possible. After I tuned it, it's generally only in CL when Im cruising at a constant speed or acceleration gently. Anytime I'm over 75% load or decelerationg in gear im in OL. It will also go to OL during fuel cut.
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Old 09-17-2010, 12:47 PM   #5
yarrgh
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It's not just 2006, it's OBDII. It's an emissions savings technique. When you're in gear and the car is driving the engine(coasting), the ECU cuts fuel. So it really is a smart idea to coast as much as you can...in gear.
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Old 09-17-2010, 01:43 PM   #6
RaineMan
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Quote:
Originally Posted by yarrgh View Post
It's not just 2006, it's OBDII. It's an emissions savings technique. When you're in gear and the car is driving the engine(coasting), the ECU cuts fuel. So it really is a smart idea to coast as much as you can...in gear.
Yep... so leave the car in gear as long as possible when approaching a stoplight. When coasting the fuel isn't reapplied until you push in the clutch.
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Old 09-20-2010, 08:23 PM   #7
RaceFaceXC
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the fuel is only ever injected when the engine rpm's are approaching idle IF the accel pedal angle is 0%. so when coasting, if you are in gear or not, the injectors are "off" until rpms approach idle. then the injectors are back "on" to keep the engine from stalling. staying in gear keeps the injectors "off" longer because engine speed stays above idle as long as wheel speed and gear selected are appropriate. It saves brakes, too. if you are good it saves the clutch and if you are real good it saves clutch, brakes, syncros and maybe a little fuel.
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Old 09-20-2010, 08:39 PM   #8
Rudgers73
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yeah I've noticed it on my 06 more since the morning have been getting colder. The whole OL under deceleration was a little weird to get used to, but I noticed I can get a nice backfire if I blip the gas and rev-match 2nd when I'm coming to a stop for an intersection haha
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Old 09-20-2010, 09:01 PM   #9
cmiovino
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When off throttle, you're in fuel cut mode as someone stated before. Great for on the highway when concerving fuel. Let the hill do the work, not your engine, heh.
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Old 09-21-2010, 02:49 AM   #10
vanquish88
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Quote:
Originally Posted by RaceFaceXC View Post
the fuel is only ever injected when the engine rpm's are approaching idle IF the accel pedal angle is 0%. so when coasting, if you are in gear or not, the injectors are "off" until rpms approach idle. then the injectors are back "on" to keep the engine from stalling. staying in gear keeps the injectors "off" longer because engine speed stays above idle as long as wheel speed and gear selected are appropriate. It saves brakes, too. if you are good it saves the clutch and if you are real good it saves clutch, brakes, syncros and maybe a little fuel.
rev matching ftw. my brakes hardly see hard condtions.
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Old 09-22-2010, 08:42 AM   #11
mshipes
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All cars after 2002 have this change.
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