Why does my Chevy Citation race at idle and slam into gear?

Short answer: If your Citation races at idle and slams into gear, fix the idle first. The slam usually goes away with it. Look for vacuum leaks (replace old cracked hoses), a sticking IAC valve or gummed-up IAC port, a broken IAC wire, and a sticking throttle cable. If the engine rocks when you shift, check the motor mounts. If the brakes ever feel hard or lock the rear wheels, check the recalls below and get the brakes inspected.

Symptom: The engine idles far too fast, and the automatic transmission bangs into Drive or Reverse. Some owners also describe a brake pedal that goes hard without power assist.

What to check first

1. Check the throttle cable for sticking first.
2. Look for vacuum leaks and replace dried-out hoses.
3. Wiggle the IAC wiring at idle and watch for an idle change.
4. Clean the IAC port, not just the valve.
5. Watch the engine as you shift to see whether it rocks, which points to the motor mounts.
6. Run your VIN for the brake recalls.

Likely causes

1. Vacuum leak. Air leaking past cracked old rubber hoses raises the idle. Members said to go over every vacuum line on a car this old.
2. Idle air control (IAC) valve or its wiring. The IAC valve sets idle speed. A new valve in a gummed-up port can still stick, and a member said the thin wires to it commonly break.
3. Sticking throttle cable or linkage. A stuck-open throttle was common on these cars, a member said.
4. Worn motor mount. If the engine rocks forward and back when you shift into gear, a motor mount is likely broken.

What it usually costs

No owner posted prices in these threads.

Is it safe to keep driving?

A car that idles high and slams into gear can lurch, so keep your foot firmly on the brake. Brake assist failures and rear brake lock-up are serious. Don't drive it until the brakes are checked. Verify with a mechanic.

DIY or shop?

DIY-friendly. Vacuum hoses, IAC wiring and throttle cables are home jobs. Brakes should be inspected by a shop.

Recalls, bulletins and complaints in plain words

• Related recalls: NHTSA lists these recalls touching this area of the Chevrolet Citation: 81V095000 and 83V018000 (1980 model year, rear brakes could lock up or skid during hard braking); 79V090000 and 82V018000 (clutch cable can rub the brake pipe at the master cylinder); 83V105000 (1983 model year, brake proportioner valves may break off and leak fluid); 83V007000 (1982 model year, rear brake hoses); 85V034000 (1984 model year, fuel leak at the throttle body fuel feed pipe). Check your VIN at nhtsa.gov/recalls. If your car is part of this recall, the dealer fixes it for free.
• Plain words: Several recalls covered rear brakes locking up in hard stops, brake lines rubbed through by the clutch cable, and proportioner valves that could break and leak brake fluid. Any of these can make the brakes behave badly. Recall 85V034000 covered a fuel leak at the throttle body. Verify with a mechanic.
• NHTSA complaints: 4 keyword-matched complaints for Chevrolet Citation 1980–1985 (of 11 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-28; keywords: idle, racing, stall, shift, slam, brake). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In 1982 Chevrolet Citation 2.5L I4 : Engine racing and transmission slamming into gear on Car Talk, an owner's inherited 1982 Citation raced at idle and slammed into gear. Members said the two were likely related: fix the idle, and the slam should go away. Their list was a vacuum leak (and replacing the old, dried-out vacuum hoses), a sticking IAC valve or a gummed-up IAC port, a broken wire between the computer and the IAC valve (wiggle the wiring at idle and watch for a change), and a sticking throttle cable. Another member said the engine rocking when shifted into gear pointed to a bad motor mount. The owner found the IAC new and free-moving, then decided to retire the car rather than pay a shop to keep hunting.
• In 1980 Chevrolet Citation hard braking on Car Talk, a former 1980 Citation owner with an automatic said the power brake assist would often fail, leading to crashes. The owner noted the rear brake lock-up problem and recall on manual-transmission cars, and an NHTSA investigation into the brakes in 1983. Another owner of an '81 said his service brakes were fine but listed the transmission, clutch, parking brake and ignition as trouble spots.

Quick tip

High idle and hard shifts on an old automatic are usually one problem, not two. Find the idle problem first.

Vehicle focus: 1980–1985 Chevrolet Citation (US).

Safety / mechanic note

Hold the brake firmly when shifting a car with a high idle. Verify with a mechanic.