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How to tell Im in open/closed loop?

Old Sep 12, 2006 | 07:09 PM
  #1  
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Default How to tell Im in open/closed loop?

My car has been getting ****ty gas milage now that its not 100 degrees out anymore. My car runs a bit cooler and I think my car might not even leave open loop (or is it closed loop?). The temp guage only goes up like 3 dashes from 130. Not even halfway on the guage. Am I running too cold. How can I test to tell whether or not my car is running correctly?
Old Sep 12, 2006 | 07:12 PM
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Default RE: How to tell Im in open/closed loop?

u need a code scanner.o to a auto store while your car is warmed up and have them check
Old Sep 12, 2006 | 07:14 PM
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Default RE: How to tell Im in open/closed loop?

what temp thermostat are you running?
Old Sep 12, 2006 | 07:16 PM
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Default RE: How to tell Im in open/closed loop?

car should operate between 180 and 200 degrees the middle dash is 200 so below that is okay, i'd be alot more concerned with running hot than cool as long as it rises from 130 up to near the middle your fine. Whens the last time the coolant was flushed and filled? Try that and replace the t stat with a 180*
Old Sep 12, 2006 | 09:53 PM
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Default RE: How to tell Im in open/closed loop?


ORIGINAL: WhiteFoxGT

My car has been getting ****ty gas milage now that its not 100 degrees out anymore. My car runs a bit cooler and I think my car might not even leave open loop (or is it closed loop?). The temp guage only goes up like 3 dashes from 130. Not even halfway on the guage. Am I running too cold. How can I test to tell whether or not my car is running correctly?
Open Loop - Startup and WOT, In this running strategy the computer is ignoring the O2 sensors.
Closes Loop - Idle and Part Throttle Cruising, In this strategy the computer is using feed back from the O2 sensors to adjust the Injector Pulsewidth.

I am not sure how one could tell if the car was in OL or CL.

However, if you pull the codes you will likely find out what the problem is.
Likely suspects are probably O2's, ECT, and ACT (but check the codes before replacing parts)

Good Luck,
jason
Old Sep 13, 2006 | 12:02 AM
  #6  
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Default RE: How to tell Im in open/closed loop?

There is no CEL on, and the car feels like its running fine and whatnot, I've just been getting pretty bad gas milage lately. I cant tell you what T-stat is in the motor because i didnt build it. I might ask the guy I bought it from. I was just curious as to a method that tells you when the computer "knows" the car is fully warmed up. I've been talkin to a good friend of mine (mustang guru) and he says running a 160 t-stat is fine. I kno all about the 180* blah blah but thats what he swears by.
Old Sep 13, 2006 | 12:45 AM
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Default RE: How to tell Im in open/closed loop?


ORIGINAL: WhiteFoxGT

There is no CEL on, and the car feels like its running fine and whatnot, I've just been getting pretty bad gas milage lately. I cant tell you what T-stat is in the motor because i didnt build it. I might ask the guy I bought it from. I was just curious as to a method that tells you when the computer "knows" the car is fully warmed up. I've been talkin to a good friend of mine (mustang guru) and he says running a 160 t-stat is fine. I kno all about the 180* blah blah but thats what he swears by.
But you're getting "****ty gas milage now "...even if the CEL doesn't turn on, you might have failure codes logged....FYI...not all the codes cause the CEL to illuminate. Need to bring the car to op temp, and run a KOER self-test...if you get rich O2 codes.....need to troubleshoot for them. The system will usually run in close loop after the O2's reach op temp (30-45 seconds) and the coolant temp is above 120° - 130°.
Old Sep 13, 2006 | 02:36 AM
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Default RE: How to tell Im in open/closed loop?

Naw, code scanner wont work at an autostore more than likely. I work at an autozone and we do free check engine tests on OBDII equipped vehicles (96 and up). 93 might require a garage for that info.

ORIGINAL: TMeyer29

u need a code scanner.o to a auto store while your car is warmed up and have them check
Old Sep 13, 2006 | 02:42 AM
  #9  
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Default RE: How to tell Im in open/closed loop?

i just use my buddys 'Genisis' scanner. Certain scanners will scan foxes. The connecter is under the hood by the drive side shock tower.


ORIGINAL: jonboy5.0

Naw, code scanner wont work at an autostore more than likely. I work at an autozone and we do free check engine tests on OBDII equipped vehicles (96 and up). 93 might require a garage for that info.

ORIGINAL: TMeyer29

u need a code scanner.o to a auto store while your car is warmed up and have them check
Old Sep 13, 2006 | 03:12 AM
  #10  
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Default RE: How to tell Im in open/closed loop?

Dont trust mustang gauges they suck. Get a real gauge( autometer, etc.).

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