Idling at 500 RPM all of a sudden?

bigcletus94

Registered User
This just started the other day. It used to idle at 700-800 which seems normal to me. Now all of a sudden, it idles at 500 and when I turn the wheel while parking, it almost dies and I can see the battery light indicator come on the dash. Could it be the alternator? It was replaced once before I bought the car three years ago.
 
i wouldnt think alternator is bad its just not turning over fast enough to turn out the light.if battery was unhooked it may take a few days to learn to idle right again i would try some injector cleaner in the gas or i like stp fuel treatment myself
 
Thanks for the quick response. The battery was unhooked about five days ago I believe. I removed my chip from the ECU because I got tired of the harsh shifts. Didn't think it would take this long though to relearn its strategies.
 
Your idle should be about 650 +-50 The sticker on the rad support tells you for sure. What have you done under the hood lately? An air leak could cause the low idle otherwise its controled by the IAC. If it were me, I'd spray clean my intake and t-body with intake cleaner before spending any cash. Good luck
 
500 rpm Idle

After unhooking the battery, when you restart the engine, you must start it at half throttle and hold for 10-15 seconds. The only thing the computer has to relearn after a disconnect is Idle Air parameter.
 
Re: 500 rpm Idle

1kewlkitten said:
After unhooking the battery, when you restart the engine, you must start it at half throttle and hold for 10-15 seconds. The only thing the computer has to relearn after a disconnect is Idle Air parameter.
HUH?
 
Re: 500 rpm Idle

1kewlkitten said:
After unhooking the battery, when you restart the engine, you must start it at half throttle and hold for 10-15 seconds. The only thing the computer has to relearn after a disconnect is Idle Air parameter.

HUH is right?
You have gotten into adaptive controls there son. there are fuel, idle and timing controls all trying to learn in the KAM memory.
http://fordfuelinjection.com/eec.html
http://fordfuelinjection.com/strategies.html

For a computer to re-learn the following must be done.
Disconnect battery for 15 minutes
Start engine and allow to idle in neutral for 4 minutes
Idle in gear around a parking lot for 45 second
Accelerate to 45MPH at 1/4 throttle should take ~10 seconds
Steady throttle of ~45MPH for 4 minutes
Decelerate to a stop and idle for 10 seconds
Accelerate to 65MPH at 1/2 throttle should take ~10 seconds
Steady throttle of ~65MPH for 4 minutes
Decelerate to 40MPH
Accelerate to 65MPH and Steady throttle for 4 minutes
Decelerate to 40MPH
Accelerate to 65MPH and Steady throttle for 4 minutes
 
vancouverBC said:
Your idle should be about 650 +-50 The sticker on the rad support tells you for sure. What have you done under the hood lately? An air leak could cause the low idle otherwise its controled by the IAC. If it were me, I'd spray clean my intake and t-body with intake cleaner before spending any cash. Good luck

I added a ZR Intake recently. I replaced the IAC from Ford last year. Could it be possible that the cold air intake could have sucked up some crap into the TB hence changing the RPM? I noticed that there is a sticker on the TB that says not to clean it. Should I just ignore that warning? What is a recommended cleaner for this? Carb cleaner? Thanks.
 
I would spray some intake cleaner on the MAF wires in case it has gotten coated with oil from the new ZR intake. My idle acted up shortly after I installed a K&N and that cured the problem. If your idle is going up and down and almost dying sometimes, I'd put clamps on both ends of the little rubber hose that goes from the intake tube to the drivers valve cover. It switches from rubber to plastic behind the DIS and covered by plug wires. Good luck
 
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