Why did the car take a long time to start: a complete analysis of the reasons and solutions

You went out to the car in the morning, turned the key - but the engine only started on the 5th try? Or does the starter turn, but the engine “sneezes” and does not start? The problem of a long start-up is familiar to every second car owner, but the reasons can be radically different. In some cases it is to blame dead battery, in others - clogged injectors or worn out fuel pump. And sometimes it’s not a matter of technology at all, but improper use.

Today we will look at all the possible reasons why the car took a long time to start - from the banal to the exotic. You will learn how diagnose the problem without visiting a service station, what symptoms indicate a specific malfunction, and what to do to return the car to a quick start. We will pay special attention to the differences between “cold” and “hot” starts - this is the key to correct diagnosis.

———

1. Battery: first suspect

If the car takes a long time to start suddenly, especially after parking overnight - the battery is to blame in 70% of cases. Even a relatively new battery can fail due to:

• 🔋 Sulfation plates - Forms during frequent short trips or long periods of idle time without recharging.
• 💧 Electrolyte boiling off - in summer due to overheating, in winter due to overcharging from the generator.
• ⚡ Leakage current — the radio, alarm system or faulty wiring “eats” charge.
• 🔌 Terminal oxidation — white coating on the contacts increases resistance.

How to check? Turn on the headlights: if they glow dimly when you try to start, the battery is discharged. Another test: when you turn the key, does the starter turn sluggishly or with “dips”? This is also a sign of a weak battery. The critical voltage for starting is below 11.8 V. At 12.4 V and below in winter, the car may not start at all.

⚠️ Attention: Do not try to “light” a car with a dead battery from a car with a running engine! This may damage the donor generator. First turn off the donor engine, then connect the wires.

———

2. Starter: when it “clicks” but does not turn

If you hear when you turn the key single clicks or a series of rapid clicks, but the starter does not rotate the crankshaft - the problem is in it or in the power circuit. Common reasons:

• 🔧 Brush wear — graphite brushes wear out, contact disappears.
• 🧲 Jammed bendix - does not engage with the flywheel.
• 🔥 Burnt contacts of the solenoid relay - the “penny” is covered with soot.
• 🔌 Winding break — the starter does not respond or turns very slowly.

Diagnostics: try starting the car “from the pusher” (for manual transmission). If the engine starts, the problem is definitely in the starter or battery. Another test: with the ignition on, close the circuit with a screwdriver Solenoid relay contacts (on the starter housing). If the motor starts spinning, the relay is to blame.

———

3. Fuel system: from the fuel pump to the injectors

If the starter turns vigorously, but the engine doesn't grasp or starts only after a long rotation - look for a problem in the fuel supply. Typical culprits:

Symptom	Probable Cause	How to check
The engine does not start, but the starter turns	Fuel pump doesn't work	Listen to the pump whirring when you turn on the ignition
Starts only after 3-5 attempts, troits	Clogged injectors	Measure the pressure in the fuel rail
Long hot start	Steam plugs in the line	Check the return fuel hose for heating
Jerky startup, black smoke	Nozzle overflow	Check the tightness of the injector valves

For injection machines are critical fuel rail pressure — norm 2.8–3.2 atm. If below 2.5 atm, the pump is not pumping enough. On carburetor auto check gasoline level in the float chamber - if it is not there, the channels or needle valve are clogged.

How to check a fuel pump without a pressure gauge?

Turn on the ignition and listen: within 2-3 seconds you should hear the sound of the pump running (buzzing from under the rear seat or trunk). If there is no sound, check the fuse (usually F3 or F15 in the block) and the fuel pump relay.

———

4. Ignition system: spark plugs, coils, wires

If the engine "sneezes" on startup or it starts only after a long rotation of the starter - the ignition system is to blame. It's easy to check:

1. Unscrew the spark plug: if it wet - fuel is supplied, but there is no spark. If dry - there is a problem with the fuel supply.
2. Check spark: insert the spark plug into the high-voltage wire, place it on the engine and turn it with the starter. There must be a spark bright blue, not reddish.
3. Measure the resistance of high-voltage wires: normal - 3–10 kOhm.

Typical faults:

• ⚡ Broken wires - the spark “goes” to ground, not reaching the spark plug.
• 🔥 Cracks in the ignition coil - especially relevant for VAG (Audi, VW, Škoda).
• 🕯️ Oily candles - often occurs with worn valve rings or seals.

⚠️ Attention: On modern cars with individual ignition coils (one per spark plug) Never remove spark plugs while the engine is running! This is guaranteed to kill the coil.

———

5. Sensors and Electronics: Hidden Culprits

Modern cars are literally “tied” to sensors. If at least one of them is lying, the ECU (electronic control unit) may block launch or fill the spark plugs with fuel. Main suspects:

• 📡 Crankshaft sensor (CPCV) - without its signal, the ECU does not know when to give a spark.
• 🌡️ Coolant temperature sensor (DTOZH) — if it’s lying, the ECU incorrectly calculates the mixture composition.
• 💨 Mass air flow sensor (MAF) - If it malfunctions, the engine starts and immediately stalls.
• 🔧 Camshaft position sensor (CPR) — affects valve timing.

How to diagnose? Connect diagnostic scanner (for example, ELM327) and check the error codes. Typical codes:

• P0335 - DPKV malfunction;
• P0115 — problem with DTOZH;
• P0100 - DMRV error.

———

6. Mechanical problems: compression, timing, oil starvation

If the car takes a long time to start gradually, and not suddenly - mechanical faults are to blame. They require serious repairs, but they can be diagnosed independently:

• 🔩 Low compression - worn rings, burnt valves or stuck rings. Checked with a compression gauge (standard: 10–14 bar in each cylinder, spread no more than 1 bar).
• ⚙️ Stretched timing belt/chain — the valve timing is off. Symptom: the engine “does not pull” and takes a long time to start.
• 🛢️ Oil fasting - if the oil is old or of poor quality, the pistons and rings “stick” when idle.
• 🔥 Thermostat problems — the engine does not warm up to operating temperature, the mixture is formed incorrectly.

How to check compression without tools? Unscrew the spark plugs, insert into the spark plug hole screwdriver and turn the starter. If the screwdriver flies out with force, there is compression. If it barely holds, the cylinder is faulty.

Unscrew the spark plugs and inspect the carbon deposits|Check the oil level and condition|Listen to the engine running for any extraneous noise|Check the timing belt tension (if accessible)|Measure the compression (if possible)-->

———

7. External factors: weather, fuel, driver errors

Sometimes the car takes a long time to start not because of a breakdown, but because external conditions. Common cases:

• ❄️ Winter launch — at −20°C, even a working battery loses up to 50% of its capacity. Solution: use preheater or “light up” from another car.
• ⛽ Bad fuel - diluted gasoline or summer diesel fuel in winter. Signs: the engine “troubles” after starting, the exhaust smells of hydrogen sulfide.
• 🚗 Short trips — if you drive only short distances, the battery does not have time to charge and the engine does not have time to warm up.
• 🔑 Incorrect startup sequence - for example, on diesels you need to wait until the heating coil of the candles goes out.

How to avoid problems?

• Use in winter synthetic oil with viscosity 0W-20 or 5W-30.
• Fill up at reputable gas stations (avoid "noname" networks).
• If the car sits for more than a week - disconnect the battery terminalto avoid discharge.

———

8. Prevention: how to avoid startup problems

To start the car with a half turn, follow simple rules:

1. Battery: clean the terminals every 3 months, check the density of the electrolyte once a year (norm: 1.27 g/cm³).
2. Fuel system: add to the gas tank every 20,000 km injector cleaner (for example, Liqui Moly or Wynn’s).
3. Spark plugs: change every 30,000–50,000 km (even if they are “still working”).
4. Oil: use semi-synthetics or synthetics with the right viscosity for your climate.
5. Sensors: check once a year Mass air flow sensor and DPKV - their malfunction often manifests itself gradually.

For diesel cars:

• Every 10,000 km drain the sediment from the fuel filter.
• Use in winter antigel (even if you refuel with “winter” diesel fuel).
• Periodically ignite particulate filter (if equipped) for a long trip on the highway.

———

FAQ: Frequently asked questions about long startup times

The car starts poorly when cold, but fine when hot. What is the reason?

This is a typical sign:

• faulty coolant temperature sensor (The ECU “thinks” that the engine is warm);
• air leakage into the intake manifold (the mixture becomes lean);
• worn out valve stem seals (oil drains into the cylinders overnight).

Start by checking the DTO and the tightness of the intake tract.

The starter turns, but the car does not start. What to do?

Algorithm of actions:

1. Check if there is spark (unscrew the spark plug and check while cranking the starter).
2. Make sure fuel arrives (listen to the operation of the fuel pump).
3. Check fuses (especially those responsible for the ECU and fuel system).
4. If everything is in order - look air leak or problems with timing phases.

Is it possible to start a car if the spark plugs are dead?

Yes, but you need them dry:

• Unscrew the candles and heat them on a gas stove (or hairdryer).
• Crank the engine with the starter 10–15 seconds no candles to ventilate the cylinders.
• Install dry spark plugs and try to start.

If the spark plugs are constantly flooding, check temperature sensor and idle air control.

Why is diesel difficult to start in winter?

Main reasons:

• Summer diesel fuel waxed in the filter.
• Glow plugs don't work (check the resistance - it should be 0.5–6 Ohm).
• In the fuel system condensation has formed (water in diesel fuel freezes).
• Low compression (critical for a diesel engine) 20+ bar in each cylinder).

Solution: use antigel and fuel filter heater.

How long can you turn the starter without draining the battery?

Rule "10–15 seconds":

• Turn the starter no longer 10–15 seconds in one try.
• Take a break 30–60 seconds between attempts to allow the starter to cool down.
• If after 3-4 attempts the car does not start, look for the reason, and do not drain the battery.

On modern cars with start-stop The system itself limits the scrolling time.