My old AMC Concord stalls at red lights. Is it worth fixing, or worth buying?

Short answer: An old AMC Concord that dies at lights usually needs basics: replace the cracked vacuum hoses and rubber fuel line, make sure the idle speed solenoid and PCV valve are there and working, and have the carburetor rebuilt instead of replaced. If you're buying one, a low-mile car that sat for years will still need hoses, belts, tires and fluids, and some parts take hunting.

Symptom: It drives fine but stalls at red lights, or the headlights flicker after a few minutes of driving. Or you're thinking of buying one and want to know what to expect.

What to check first

1. Replace old vacuum hoses and look for disconnected or capped-off ones.
2. Check that the idle speed solenoid and PCV valve are installed and working.
3. Inspect the rubber fuel lines from the tank forward for cracks.
4. With the lights on, wiggle wires and ground straps, and check charging voltage with the engine running.
5. If buying, check for rust, sitting damage (dry rubber, old tires, stale fuel), and find a mechanic who knows carburetors.

Likely causes

1. Missing or bad idle speed solenoid. The idle speed solenoid holds the throttle open a bit so the engine doesn't stall at a stop, especially with A/C on.
2. Cracked vacuum hoses. On a car this old, nearly every rubber vacuum hose may be cracked, and each one causes poor idle.
3. Rotted rubber fuel line. A cracked section of rubber fuel line near the tank can suck air and starve the carburetor.
4. Carburetor needing repair. Members said the carburetor usually needs repair or a rebuild, not replacement.
5. Loose connection or charging voltage swings (flickering lights). Headlights that flicker after a few minutes can be a loose wire or ground, or voltage swinging up and down.

What it usually costs

Owners in these threads didn't post prices.

Is it safe to keep driving?

Stalling at lights is a hazard because you lose power brakes and steering. Old rubber fuel lines can leak and catch fire. Fix both before regular driving.

DIY or shop?

Hoses, the PCV valve, fuel line and wiring checks are DIY. A carburetor rebuild is DIY if you're patient, or a job for an old-school shop.

Recalls, bulletins and complaints in plain words

• Recalls: NHTSA's recall and complaint lookups returned no data for this model in these years, which is normal for a car this old. Check your VIN at nhtsa.gov/recalls. If your car is part of a recall, the dealer fixes it for free.
• Plain words: The complaint count below shows how often owners reported problems that mention these words to NHTSA. A count is not proof of a defect.
• NHTSA complaints: 0 keyword-matched complaints for AMC Concord 1978–1983 (of 0 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-30; keywords: stall, idle, carb, light) (NHTSA returned no data for 12 model-year queries). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In 1979 AMC Concord on Car Talk, a 1979 Concord owner had already had the carburetor replaced and still had the engine die at red lights. The mechanic said the idle speed solenoid was missing, and the PCV valve was missing too. Members said to check the fuel line, said the carburetor should be repaired rather than replaced, and said nearly every vacuum hose probably needs replacing.
• In Am i crazy? i'm thinking of buying a '78 AMC concord on Car Talk, a buyer asked about a '78 Concord with 27,000 miles as an evenings-and-weekends car. Members warned that low-mile cars that sat a lot start showing age once driven, that parts may be harder to find, that these cars came from an era of low power and weak mileage, but also that the simple carbureted setup has less to go wrong.
• In AMC Concord electrical problem on Car Talk, a 1978 Concord wagon with the 304 V8 had headlights flickering after 4 or 5 minutes, even after a new battery, dimmer switch and fuse. Members said to shake every wire and ground strap with the lights on, and to watch charging voltage with an analog meter for swings between about 13 and 14.5 volts.

Quick tip

These are simple cars. Most of what goes wrong is 40-year-old rubber. Replace the hoses first and you'll be surprised how well it runs.

Vehicle focus: AMC Concord sedan, coupe and wagon, 1978-1983, six and V8.

Safety / mechanic note

Stalling and fuel leaks are safety items. Verify with a mechanic.