What Causes the Need to Start the Engine Multiple Times When Cold?

[VanCarter]

Reasons why a cold engine requires multiple attempts to start: 1. After the vehicle has been parked overnight, fuel in the fuel lines flows back into the fuel tank, resulting in insufficient fuel pressure during startup. Inspection method: Connect a fuel pressure gauge to the fuel line, turn on the ignition, and the gauge should read around 320kpa. 2. Faulty coolant temperature sensor. Inspection method: Use a multimeter to measure the resistance and voltage of the coolant temperature sensor. 3. Insufficient or uneven cylinder compression across cylinders. Inspection method: Use a compression tester to measure the compression of each cylinder. 4. Faulty carbon canister purge solenoid valve. Since the carbon canister purge solenoid valve operates in a closed-loop control system, it also activates when starting the vehicle in the morning, enriching the air-fuel mixture and causing improper combustion. Inspection method: Use a 431 scanner to read fault codes.

[DeZoey]

Last time I encountered this situation, replacing the battery fixed it. It's especially noticeable in winter—the starter motor turns over with great difficulty, like a phone stuttering when it's almost out of power. Old car batteries rarely last more than three years. Use a multimeter to check the starting voltage; if it's below 10 volts, replace it immediately. Excessive carbon buildup can also cause this issue—the intake valves get coated with a layer of black sludge, and most of the injected fuel gets absorbed. Another possibility is a leaking fuel pressure regulator; if the fuel lines can't hold pressure after shutdown, you'll need to pump multiple times to restart. The trickiest culprit is an aging crankshaft position sensor—its signal drifts when cold, making the ECU miscalculate the ignition timing. To save money, start by cleaning the throttle body. If that doesn't work, check the fuel pump's pressure retention capability.

[Maya]

As an experienced driver, I've encountered this too many times. If you hear a clicking sound on the first ignition attempt, it's usually a weak battery. A whirring sound without starting indicates fuel system issues. Focus on the fuel pump pressure relief valve - most new cars use plastic components which are prone to cracking and fuel leakage in cold weather. When you first turn the key, listen for the fuel pump's humming sound; it should last at least three seconds. Don't ignore throttle body carbon buildup either - I just cleaned mine with carburetor cleaner last week and now it starts instantly. If your spark plugs have over 40,000 km, replace them immediately as widened gaps cause weak ignition. If you can't identify the problem, have a shop check cylinder compression - anything below 9 bars means you're burning oil.

[CharlesMarie]

I know exactly how that feels! Last time the dealership diagnosed it as a camshaft position sensor issue. When the engine is cold, metal contracts, increasing the sensor gap and causing signal problems. You can test the starting voltage yourself—if it's below 11V, consider replacing the battery. Also, don't use just any engine oil; 5W viscosity is thin enough for winter. Once I forgot to turn off the dashcam and drained the battery—the next morning, starting the car was like an asthma patient gasping for air. Now I've developed good habits: turning off the AC and headlights before shutting down to give the battery a break. For older cars, it's best to keep a jump starter handy to avoid getting stranded in winter.