My 87 has closed loop timers that are set in the bin as well as temp for CL. Temp for knock sensor too. All can be set to meet your needs.
Closed loop temp?
Thread Starter
Melting Slicks
Joined: Nov 2010
Posts: 2,216
Likes: 112
From: Michigan
Closed loop temp?
Ok I was just reading about closed loop some because I have my intake apart and was considering running a 180 t-stat. I like to use a 160 t-stat for my cars so I know it's open when I race, because my cars usually run cool. It's a small diff but every little bit helps and I am not here to debate ideal operating temp.
My question is what temp does closed loop happen? My car will drop to 150's at cruise, but it seems to get good mileage so can I assume it's closed? I ask because the guy who did my chip said it sometimes can be as high as 165 and my fan is set to 190/on & 165/off, so if I put a 180 in my fan could be on a lot more when I race and that would draws more amps(I know I could wire in a switch). So then I could have a fan on and t-stat closed when on the line.
My question is what temp does closed loop happen? My car will drop to 150's at cruise, but it seems to get good mileage so can I assume it's closed? I ask because the guy who did my chip said it sometimes can be as high as 165 and my fan is set to 190/on & 165/off, so if I put a 180 in my fan could be on a lot more when I race and that would draws more amps(I know I could wire in a switch). So then I could have a fan on and t-stat closed when on the line.
Race Director
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From: Database Error Indiana
Race Director
Joined: Apr 2002
Posts: 10,036
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From: Anaheim CA
You can use the SES light to determine if you are in closed loop or open loop mode.
Short ALDL terminals A & B together AFTER you turn on the ignition (or while the engine is running). The SES light will flash 2-1/2 times per second in open loop and once per second in closed loop.
Short ALDL terminals A & B together AFTER you turn on the ignition (or while the engine is running). The SES light will flash 2-1/2 times per second in open loop and once per second in closed loop.
Race Director
Joined: Apr 2002
Posts: 10,036
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From: Anaheim CA
Engine run time > 300 seconds (cold) if startup coolant temperature < 58.5°F
Engine run time > 206 seconds (warm) if startup coolant temperature > 58.5°F and < 158.5°F
Engine run time > 50 seconds (hot) if startup coolant temperature > 158.5°F
Regardless of these parameters, the O2 sensor must reach operating temperature and be active before the ECM will go into closed loop mode.
Thread Starter
Melting Slicks
Joined: Nov 2010
Posts: 2,216
Likes: 112
From: Michigan
I put the 180 in for now, I'll prob try another tune place for spring since the last guy isn't very responsive.
Thx for the info I'll have them set lower KS temp at least if my car continues to cruise cold, pretty sure it did before I changed to the 160 t-stat even with the stock chip.
Thx for the info I'll have them set lower KS temp at least if my car continues to cruise cold, pretty sure it did before I changed to the 160 t-stat even with the stock chip.
Safety Car
Joined: Sep 2001
Posts: 4,150
Likes: 551
From: Glenbeulah Wi
Ok I was just reading about closed loop some because I have my intake apart and was considering running a 180 t-stat. I like to use a 160 t-stat for my cars so I know it's open when I race, because my cars usually run cool. It's a small diff but every little bit helps and I am not here to debate ideal operating temp.
My question is what temp does closed loop happen? My car will drop to 150's at cruise, but it seems to get good mileage so can I assume it's closed? I ask because the guy who did my chip said it sometimes can be as high as 165 and my fan is set to 190/on & 165/off, so if I put a 180 in my fan could be on a lot more when I race and that would draws more amps(I know I could wire in a switch). So then I could have a fan on and t-stat closed when on the line.
My question is what temp does closed loop happen? My car will drop to 150's at cruise, but it seems to get good mileage so can I assume it's closed? I ask because the guy who did my chip said it sometimes can be as high as 165 and my fan is set to 190/on & 165/off, so if I put a 180 in my fan could be on a lot more when I race and that would draws more amps(I know I could wire in a switch). So then I could have a fan on and t-stat closed when on the line.
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Racer
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You can use the SES light to determine if you are in closed loop or open loop mode.
Short ALDL terminals A & B together AFTER you turn on the ignition (or while the engine is running). The SES light will flash 2-1/2 times per second in open loop and once per second in closed loop.
Short ALDL terminals A & B together AFTER you turn on the ignition (or while the engine is running). The SES light will flash 2-1/2 times per second in open loop and once per second in closed loop.
Race Director
Joined: Apr 2002
Posts: 10,036
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From: Anaheim CA