PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

cant get pcm to open loop

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Old Sep 14, 2006 | 11:57 AM
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Unhappy cant get pcm to open loop

Ive tried using bidirectional controls to no avail. Went into table b4205 closed loop temp enable and set to 250. flashscan still telling me closed loop. Any thoughts?
Thanks scott
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Old Sep 14, 2006 | 12:01 PM
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Is the maf set to fail?
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Old Sep 14, 2006 | 12:18 PM
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Are you running the latest version of the software
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Old Sep 14, 2006 | 01:07 PM
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Originally Posted by Doc
Is the maf set to fail?
MAF failure is for speed density, not open loop. Two totally different things. Speed density fueling calculations can still rely on the O2's for corrections (ie closed loop).

Open loop simply means the PCM doesn't adjust fueling based on the O2 sensors. It's basically like a carb'd setup where you set the fueling and go.
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Old Sep 14, 2006 | 03:03 PM
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Originally Posted by SSpdDmon
MAF failure is for speed density, not open loop. Two totally different things. Speed density fueling calculations can still rely on the O2's for corrections (ie closed loop).

Open loop simply means the PCM doesn't adjust fueling based on the O2 sensors. It's basically like a carb'd setup where you set the fueling and go.
Very good, I knew that! Brain fart.
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Old Sep 14, 2006 | 03:21 PM
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I knew you knew that Doc. I just thought I'd elaborate for the newbs.
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Old Sep 14, 2006 | 03:22 PM
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Doc I had forgot all about setting it to 1hz. When I get home tonight I will try and see if it changes any thing as always your a great help
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Old Sep 14, 2006 | 05:13 PM
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changed maf fq as stated has little or nothing to do with open or closed loop operation.
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Old Sep 14, 2006 | 06:05 PM
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Oh crap, please listen to ffof67 and SSpeed...I was just scatterbrained-too many irons in the fire at once. As stated before, Speed Density has nothing to do with weather or not the car is in open or closed loop fueling, it merely implies your use of a maf. Sorry for the confusion. I wish I had a valid excuse for my faux pas but sadly, working 70 hours/a week for Uncle Sam and 30hrs for side projects is not a sufficient excuse on the subject for me- I need a vacation.
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Old Sep 14, 2006 | 06:13 PM
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Scott et all,
Forgive me for not asking this in the first place....You are not in Open loop when you "should be?" Correct? Which project are we talking about? Overall I assumed I knew which project/surrounding circumstances you were talking about and went off on a tangent that may or may not apply to your situation. Scott, let us know more about this project.
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Old Sep 14, 2006 | 06:33 PM
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For lose that don’t know I swapped my 98 pcm for a 02. went to Holden crazy an got a file 99 to 02 os truck runs like crap even after swapping the 98 ve table. I don’t have a wide band yet but I thought that I could get it to run somewhat decent without it. So my thought was to set up open loop for time being right now all I have to do is move the truck around till its painted. Im sure its something im doing wrong but cant get it to switch to ol ive tried bidirectional controls and cl temp enable. The only mods to the engine no maf no egr any ideas or thoughts would be appreciated
scott
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Old Sep 15, 2006 | 12:34 PM
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My problem with cl was do to fuel psi still don’t understand still why I cant go ol
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