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Old 12-06-2009, 07:08 PM   #1 (permalink)
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How long should an engine stay in open loop after start

I tried shutting off my engine at some long lights, and I noticed that after I started it stayed in open loop for 5-10 seconds(Using the scangauge). It was a warm engine, 200+ degrees on the water temperature. Has anybody else encountered this? BTW, I noticed that it doesn't stay in open loop if you bump start it. I'm wondering if somehow the ECU is programmed to stay in open loop for a set period of time after the starter is used? Or is there possibly something wrong here?


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Old 12-06-2009, 07:13 PM   #2 (permalink)
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I think you are right about the ecu automatically running open loop.nt

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Old 12-11-2009, 01:58 PM   #3 (permalink)
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Old 12-11-2009, 04:40 PM   #4 (permalink)
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bombloader -

For my car in my mild SoCal climate, my cold start in the morning is about 52 seconds :

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Last edited by cfg83; 12-11-2009 at 06:35 PM..
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Old 12-11-2009, 06:32 PM   #5 (permalink)
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bombloader -

Quote:
Originally Posted by bombloader View Post
I tried shutting off my engine at some long lights, and I noticed that after I started it stayed in open loop for 5-10 seconds(Using the scangauge). It was a warm engine, 200+ degrees on the water temperature. Has anybody else encountered this? BTW, I noticed that it doesn't stay in open loop if you bump start it. I'm wondering if somehow the ECU is programmed to stay in open loop for a set period of time after the starter is used? Or is there possibly something wrong here?
I have seen the same thing when starting my toasty-warm engine at a stoplight.

With bump starts after EOC, it stays in open loop for maybe something under 5 seconds. I have a theory (or hope?) that if I enabled a kill switch in place of my current ignition off/on scenario, the ECU/PCM *might* stay in closed loop the whole time. However, it also might get upset when it observes a lean condition in the 02 sensor during EOC. But, I have yet to enable a kill switch, so I can't say either way for sure.

CarloSW2


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