QuestionA few weeks ago, my 2004, (4 cylinder manual) Hyundai tiburon started idling up to 3000 rpm almost every time while at a complete stop. With my foot on the brake, i would push down on the clutch and let out slowly to get the revving/ high idle to go down. Also recently when i start my car, take off, and accelerate, it jerks me like a bucking jerk as i push down on the gas peddle to accelerate. Once i get going after a few minutes, the bucking goes away.
AnswerThis is consistent with a defective throttle position sensor or a large vacuum leak. I'd also expect there may be a diagnostic trouble code stored in the engine control module (ECM).
If you know what you're looking for, start with looking for vacuum or air intake leaks. Is the bellows between the air flow sensor and throttle body securely attached? Is the PCV hose intact? The purge hose? The brake booster hose?
If you don't really know what you'd be looking at, take the car somewhere that'll read your trouble codes for free such as AAMCO or AutoZone and report back. If you have a trouble code stored, I can advise you how to proceed once I have that information.
