'94 Mustang: Rough Idling on Start

Discussion in 'The Safe Zone' started by Ereinion, Nov 6, 2020.

  1. Ereinion

    Ereinion New Member

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    Mar 20, 2019
    Hi folks,
    I don't know much about cars but I'm trying to learn. My good old '94 Stang has been such a faithful little car, and I love driving her.

    1994 Ford Mustang (base)
    V6, manual transmission
    mileage: unknown (estimated > 250k)

    Lately though, she's had a lot of trouble when I first start her up. It seems to be worse on cold days (below 40F), although it's not limited to that either. It seems to be more related to the cold season than the current temperature when I start her.

    Anyway, when I first start her she turns over and starts without a problem, then idles very roughly for 10-15 seconds. She struggles to stay running, rattles and vibrates a lot, and nearly stalls out several times. It doesn't seem to make any difference whether I engage the clutch or not. Then, after several seconds, she'll rev the engine really high and the tachometer shoots up. Usually this calms down after several seconds and she runs fine, but sometimes she'll keep running at high RPM for a while, making it difficult to drive (sometimes I have to partially engage the clutch to keep the speed down).

    I don't know if this is normal for a car of her age, in the winter, or if there's something else going on? Any tips?