1. Please sign in or join the Thunderbird club free to access the search page and many other free site features.
    If you forgot your password click here.

    Click the "X" to the right to dismiss this notice.
    Dismiss Notice

1997 Ford Thunderbird 4.6 rough idle when shifting into gear

Discussion in '1989 - 1997 Ford Thunderbird' started by Jtavares88, Jun 12, 2019.

  1. Ive owned my 97 TBird for about a month. Since ive bought the car its had a bit of a rough idle when i first shift into gear or I can sometimes feel it coming to a stop. I it may just need plugs and wires so I performed a whole tune up. Still vibrates after new plugs and wires and rest of tune up. After work today I'm going to check for vacumm leaks. Does anyone have any idea what the issue could be?
  2. 64ZCODE

    64ZCODE Well-Known Member Gold Donor

    Hi there. It could be the EGR valve sticking partially open. The way to tell is to hook up a hand vacuum pump to the valve and put suction on it, at which point the engine should stumble and die. If it doesn't, then the valve isn't working properly.

    Also, does the car have an intake air control valve (IAC)? It's a valve that opens and closes to control idle speed. If the IAC valve sticks, it can cause a rough idle. Locate the IAC and give it a few taps with a hammer and see if the idle stabilizes. Tapping on the IAC frees up the valve to close and is the way to diagnose the problem. If that is the problem, then the IAC should be removed and it may be possible to clean it or else it will need to be replaced.


Help us by sharing/liking this page!

Shop Amazon.comPlease shop Amazon.com using this link to support the forum!