[freddy1313]

I have a 1999 V6 Mustang that I got in June, and I've had no problems with it up till now. Usually my mustang starts idling high, then drops to between 750 and 1000 rpms. Last night I took the dash apart, and before I did, I disconnected the battery (not sure if this is relevant), and now when i start the engine, it drops quickly to below 500 rpms, almost to a stall, then it revs up and down. (Sounds like i'm revving my engine). After a minute, it goes away and seems to be just fine... But when i turn it off and start it again, it repeats the same thing. Any help would be greatly appreciated.. since i'm not exactly great with cars. Thanks.

[dakine858]

Originally Posted by freddy1313

I have a 1999 V6 Mustang that I got in June, and I've had no problems with it up till now. Usually my mustang starts idling high, then drops to between 750 and 1000 rpms. Last night I took the dash apart, and before I did, I disconnected the battery (not sure if this is relevant), and now when i start the engine, it drops quickly to below 500 rpms, almost to a stall, then it revs up and down. (Sounds like i'm revving my engine). After a minute, it goes away and seems to be just fine... But when i turn it off and start it again, it repeats the same thing. Any help would be greatly appreciated.. since i'm not exactly great with cars. Thanks.

You might have a drained battery, or you didn't properly re-connect your battery cables. Start your car and let it run for 20 min so the battery gets fully charged by the alternator.

[freddy1313]

I took her for a 20 min drive..(if that'd work as well?) still no difference. When i stop at stop signs i seem to nearly stall sometimes.

[dakine858]

Originally Posted by freddy1313

I took her for a 20 min drive..(if that'd work as well?) still no difference. When i stop at stop signs i seem to nearly stall sometimes.

That sounds like your have a bad Throttle Position Sensor. My next guesses would be a clogged fuel filter, or a dirty/bad Mass Airflow Sensor.