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Old 05-12-2005, 03:26 PM   #1
boxxxer
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Default Closed loop / open loop controlled by throttle position sensor?

Is the closed loop / open loop transition controlled by the throttle position sensor, or a combination of sensors?
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Old 05-12-2005, 06:15 PM   #2
bofh
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TPS, EGT, and ECU. On older cars (03-) it is mainly TPS. Vaus made a gimmick to trip OL by fudging the TPS. On newer cars (04+) there is the dreaded delay. It may or may not be also delays with the EGT trigger, but no one has tested it. Check the thread on Vaus's gadget to understand it more.
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Old 05-12-2005, 06:28 PM   #3
hippy
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rpm too
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Old 05-12-2005, 07:26 PM   #4
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Definitely TPS and RPM, but I've never heard of this EGT trigger. Obviously it's not there on the STi (no EGT probe). What is the criteria on the WRX based on the EGT probe? Are you sure you're not talking about the "emergency limp mode" thing to save the pre-cat? I wouldn't really classify that as something involved in the normal closed -> open loop transition.
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Old 05-12-2005, 07:34 PM   #5
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There is a forced switchover at 1900 degrees for EGTS on the wrx. I don't know why...I think the engine would have melted at that point anyway. Also, I think engine load can force the switchover as well.

Mike
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Old 05-13-2005, 09:44 AM   #6
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Quote:
Originally Posted by crazymikie
There is a forced switchover at 1900 degrees for EGTS on the wrx. I don't know why...I think the engine would have melted at that point anyway. Also, I think engine load can force the switchover as well.

Mike
That's just about as useful as the 3psi oil pressure light.
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Old 05-13-2005, 09:49 AM   #7
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From what I remember from looking at the AF423 rom file ('02 MT/AT). It was anything over 3900 RPM was an immediate kick out .OR. anything over 69% TPS .OR. any load over 5-6 MS of on time. Don't quote me on the last one though. Ecutek didn't exactly have a very precise explanation in the software.

But the 3900 RPM was regardless of TPS or load.

Under 3900 RPM either of the two conditions being exceeded would trigger OLF.

For the sake of completeness, in the case of the UTEC, IIRC. Anything over 5k RPM also triggered OLF regardless of the TPS cross over.

Jorge (RiftsWRX)
www.ProjectWRX.com
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Old 05-13-2005, 04:06 PM   #8
boxxxer
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Thanks for all the replies!! You have probably seen some of my threads trying to gather information on the cl / ol lean condition on 04's and how it relates to adding a TBE and Up, if not, thats what I'm looking for.

I would really appreciate everyones thoughts on how adding a TBE / gutted up on an 04 running the stock ECU would make this condtion worse.

I have gotten some replies in the sticky "WRX detonation cause found" at the top of 2.0 l forum.

From that thread and this one I have come to the following conclusion...

an 04 WRX with a stock exhaust and up vs the same WRX with a TBE / gutted up (both running the stock ECU) would be exposed to the same part throttle lean burn time during the cl / ol transition...the difference being where in the RPM band the lean burn condition happened.


therefore

Running an 04 WRX with the stock ECU and a TBE / gutted up is no worse for the motor than the way it came stock.

What do you think?

Last edited by boxxxer; 05-13-2005 at 07:08 PM.
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Old 05-13-2005, 10:03 PM   #9
bofh
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It would be easier to discuss this if you kept it in one thread. I can't even remember which one I replied last in.
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Old 05-16-2005, 12:12 PM   #10
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You're right. I'll keep this discussion going in the 2.0 l "Detonation cause found" thread.
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