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runs better in open loop mode... why

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runs better in open loop mode... why

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Old 06-08-2013, 06:50 PM
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streetsteve
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Default runs better in open loop mode... why

I did do a search first and didn't find what I was looking formy car seems to run better in open-loop mode, feels faster accelerates faster, seems like after its fully warmed up I try to accelerate if feel sluggish and not as fast only mods done to the car are offroad x pipe with pypes violator mufflers, 4:10 gears, JLT intake, SCT tuner with a Bama tune was thinking it might be the o2 sensors I don't have any check engine light or trouble codes I do have an intermittent battery light but doubt that has anything to do with the problem, any ideas as to what this might be, ive also checked for Intake leaks and found none
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Old 06-10-2013, 01:53 PM
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The02GT
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O2 sensors.
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Old 06-10-2013, 02:49 PM
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Derf00
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Was the battery light intermittent before or after the problem started?

Intermittent battery light may have everything to do with it. A weak alternator will cause that battery light to come on or flicker. Low charging system voltage means decreased voltage to the ignition system (spark) and could also slow down the reponse time from engine sensors that make adjustments to your A/F.

When your car is warmed up it's made even worse because Heat increases electrical resistance.

I'd fix that first then see if the problem persists.

P.S. Open loop tyically only lasts about 30 seconds, after that the car goes to closed loop.
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Old 06-11-2013, 01:08 PM
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^+1, all 110% factual and solid advice...
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Old 06-11-2013, 02:39 PM
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uberstang1
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Replace alternator.
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Old 06-11-2013, 03:15 PM
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streetsteve
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I checked charging system and its 14.47 volts while running and when the battery light is on it was the same, I turned on all the lights and a/c and pressed the brakes and voltage dropped to 13.9 volts
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Old 06-11-2013, 03:28 PM
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Derf00
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Originally Posted by streetsteve View Post
I checked charging system and its 14.47 volts while running and when the battery light is on it was the same, I turned on all the lights and a/c and pressed the brakes and voltage dropped to 13.9 volts
You didn't answer my first question.

I'd have the alternator taken off and bench tested or tested while on the car with a load tester.

Under speed (while driving) you'd be surprised how much current (amperage not voltage) your ignition system actually uses. A load test checks amperage AND voltage. I should have been more concise in my first post and suggested a load test to begin with.

Until you resolve the obvious issue (related or unrelated) you are possibly chasing your tail.

You're also wasting people's time by having two threads open on the same topic.

https://mustangforums.com/forum/gene...-mode-wth.html

Last edited by Derf00; 06-11-2013 at 03:30 PM.
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Old 06-11-2013, 03:34 PM
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streetsteve
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Sorry the battery light has been intermittent ever since I have owned the car, 6 months now, noticed problem about 3 months ago when I started modding the car
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Old 06-11-2013, 03:44 PM
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Derf00
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Ok then. Given that piece of info the battery light/charging item seem less likely to be the culprit although. Still, get it checked out. (Edit: Because until you 100% rule it out, you never know).

I live in AZ too and 6 months ago it never hit over 70-75 degrees. For the last couple months it's been 90+ almost every day and for the last few weeks 100+. Ambient temps under our hoods get way hotter here than other places (lower humidity) putting even more stress on electrical. I'm guessing your problem has gotten worse since it started heating up?

What mods have you added and how soon after your last mod did the problem start?

Last edited by Derf00; 06-11-2013 at 03:54 PM.
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Old 07-17-2013, 09:43 PM
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streetsteve
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Has had this problem regardless of the mods.. also an update, replaced my o2 sensors and replaced my coils with the accel coils, car still runs like a raped ape before temp gauge gets to the middle of the gauge, then just feels like I lost 20 or 30 hp,
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