The car does not start the first time: how to find and eliminate the cause

You turn the ignition key, but the engine refuses to start on the first try - is this a familiar situation? The problem when the car does not start the first time can turn the morning commute to work into a real quest. There are dozens of reasons for this behavior: from a discharged battery to complex malfunctions of the fuel system. In this article we will look at 12 most common reasonswhy a car doesn’t start well when cold or hot, and we’ll also give step by step instructions for diagnostics and troubleshooting.

It is important to understand that the nature of the fault often depends on conditions: e.g. diesel engines more often refuse to start in cold weather due to fuel waxing, and gasoline engines - due to ignition problems. We will look at the symptoms for different types of engines, and will also focus separately on cases when the car starts the second or third time, but then works normally. If you are not an auto electrician, don’t worry - most problems can be solved yourself with a minimum set of tools.

1. Discharged or faulty battery

The most obvious and common reason why a car does not start the first time is battery problems. Even if the battery is not completely dead, its capacity may not be enough to reliably start the starter. This is especially true in winter, when the engine oil thickens and the chemical reactions in the battery slow down.

How to check:

• 🔋 Terminal voltage there should be no load 12.6–12.9 V. When 12.0–12.3 V - battery low, below 11.8 V - deep discharge.
• 🔧 Test under load: When starting the engine, the voltage should not drop below 10 V.
• 👀 External inspection: terminal oxidation, case swelling, electrolyte leakage - signals for replacement.

If the battery is low, try using another car or use a jump charger. Modern batteries with technology AGM or EFB You can’t charge with cheap “chargers” - this reduces their life by 2-3 times.

2. Starter malfunctions: symptoms and solutions

When you turn the key you hear relay clicks, but the starter does not turn the engine, or the rotation is too slow - it is he who is to blame. The starter can fail for several reasons:

• ⚙️ Brush wear or collector - requires disassembly and replacement.
• 🧲 Short circuit or winding break - checked with a multimeter.
• 🔗 Bendix problems (overrunning clutch) - a grinding noise is heard when starting.
• 🔌 Oxidation of contacts on the solenoid relay.

For diagnostics:

1. Remove the starter and check its operation on the table by connecting it to the battery.
2. Measure the resistance of the windings: the norm for most models is 0.1–0.5 Ohm.
3. Check the movement of the Bendix gear - it should move easily in one direction and be blocked in the other.

Check the voltage on the solenoid relay control wire (should be 12V when turning the key)

Inspect the brushes for wear (minimum length - 7-8 mm)

Turn the starter manually - there should be no jams

Check the integrity of the flywheel teeth (through the inspection window of the box) -->

If the starter hums but does not engage the flywheel, the problem may be worn flywheel ring — replacing it requires removing the gearbox.

3. Problems with the fuel system

When the engine does not start the first time, but then catches on, it is often to blame fuel system. Symptoms:

• 🚗 The engine “has enough”, but immediately stalls.
• 🔥 The smell of gasoline from the exhaust pipe (fuel overflow).
• ⏳ Long startup (the starter spins for 5-10 seconds before catching).

Main reasons:

Malfunction	Symptoms	Solution
Clogged fuel injectors	The engine stalls after starting, high fuel consumption	Ultrasonic cleaning or liquid cleaning
Faulty fuel pump	Weak pressure in the ramp, the engine stalls while driving	Replacing the pump or its strainer
Air leak in the fuel line	Long startup, floating speed	Checking the tightness of hoses and clamps
Dirty air filter	Loss of power, black smoke from the exhaust	Replacing the filter (every 15–20 thousand km)

To diagnose the fuel system:

1. Check the pressure in the rail (the norm for most injection cars is 2.8–4.0 bar).
2. Scan for errors ECU (for example, P0171 - lean mixture P0300 — misfires).
3. Inspect the spark plugs: if they are wet, this is a sign of overfilling of fuel.

4. Ignition system malfunctions

Ignition problems manifest themselves as follows: the starter turns, but the engine does not “catch” or starts after 3–5 attempts. Culprits:

• ⚡ Spark plugs: wear of electrodes, carbon deposits, cracks in the insulator.
• 📶 High voltage wires: insulation breakdown, contact oxidation.
• 🔧 Ignition coils: interturn short circuit or open circuit.
• 📡 Ignition module (on old cars): failure of transistors.

How to check:

1. Candles: Unscrew and inspect. Normal clearance - 0.7–1.0 mm for gasoline internal combustion engines. Carbon deposits on the electrodes indicate a rich mixture or oil in the combustion chamber.
2. Wires: in the dark when starting the engine there should be no visible discharges (blue glow). Check the resistance with a multimeter (normal is 3–10 kOhm per meter of length).
3. Reels: Swap with a known good one. If the problem moves to another cylinder, the coil is faulty.

On diesel engines they play a similar role glow plugs. If they fail, the engine will have difficulty starting when cold. Checked with a multimeter (resistance - 0.5–6.0 Ohm) or visually (after 10 seconds of glow, the candle should glow red).

5. Sensors affecting engine starting

Modern cars are equipped with dozens of sensors, and failure of even one can lead to starting problems. The most critical:

• 🌡️ Coolant temperature sensor (DTOZH): if he is lying, the ECU incorrectly calculates the mixture composition.
• 💨 Mass air flow sensor (MAF): If there is a malfunction, the engine “chokes” with fuel.
• 🔄 Crankshaft position sensor (CPS): Without its signal, the ECU will not give the injection command.
• 🚗 Camshaft position sensor (CPR): affects valve timing.

How to diagnose:

1. Read errors to the scanner (eg. ELM327). Codes P0115–P0119 - problems with DTOZH, P0335–P0339 - DPKV.
2. Check the resistance of the sensors with a multimeter (for example, for DTOZh the norm is 2–5 kOhm at +20°C).
3. Inspect the connectors for oxidation or broken wires.

What to do if there is no scanner for diagnostics?

You can use the “scientific poking method”:

1. Disconnect the sensor connectors (mass air flow sensor, air flow sensor) one by one.

2. If after switching off the engine starts better, the sensor is faulty.

3. This method is not suitable for DPKV - without it, the engine will not start at all.

On Volkswagen, Audi and Skoda with engines 1.8T and 2.0T a common problem is failure oil pressure sensor. It can block starting if the ECU “sees” low pressure.

6. Problems with alarm and immobilizer

If the car does not start the first time, but the starter turns, and the fuel and ignition are in order, the culprit may be anti-theft system. Symptoms:

• 🔑 The immobilizer light on the panel lights up or flashes.
• 🚨 The alarm goes off when you try to start.
• 🔄 The engine starts and immediately stalls (the ECU blocks the fuel pump).

What to do:

1. Try starting the engine with the second key fob.
2. Check the fuses responsible for the immobilizer (usually F10–F20 in the block).
3. If the alarm activates spontaneously, reset its settings (instructions are in the car manual).
4. On some cars (for example, Renault) the key “learning” procedure helps: insert the key → turn on the ignition for 10 seconds → remove the key → repeat 3 times.

On Toyota and Lexus with the system Smart Key A common problem is the battery in the key is low. Even if the key fob works at a distance, to start the engine the voltage must be at least 2.8 V.

7. Engine mechanical problems

If all electrical systems are in order, but the car stubbornly does not start the first time, the reasons may lie in mechanics:

• 🛢️ Low compression in the cylinders (piston ring wear, valve sticking).
• 🔗 Timing problems: stretched belt/chain, broken marks.
• 💧 Oil leak through seals or gaskets (for example, a valve cover gasket).
• 🔥 Valve burnout or piston (diagnosed by smoke from the exhaust and tripping).

How to check compression:

1. Unscrew all spark plugs.
2. Insert the compression gauge into the spark plug hole.
3. Crank the engine with the starter (5–7 seconds).
4. The norm for gasoline internal combustion engines is 10–14 bar, for diesel engines - 25–35 bar.

If compression is low, fill the cylinder 20–30 ml oil and repeat the measurement. If the indicators have increased, the piston rings are to blame; if not, there is a problem with the valves or cylinder head gasket.

What to do if the car doesn’t start the first time: step-by-step algorithm

To avoid wasting time guessing, follow this plan:

1. Check the battery:
   • Terminal voltage without load.
   • Condition of the terminals (oxidation, poor contact).
2. Diagnose the starter:
   • Can you hear the solenoid relay clicking?
   • Does the starter turn vigorously or “barely”?
3. Check the fuel system:
   • Is there gasoline in the tank (yes, this happens!).
   • Can you hear the sound of the fuel pump when you turn on the ignition?
4. Inspect the ignition system:
   • Spark on the spark plugs (checked with a special tester or “ground”).
   • Condition of high-voltage wires.

Read ECU errors (even if not Check Engine, errors may be in memory).

Check immobilizer:

• Is the light on the panel blinking?
• Try the second key.

If after all the checks the problem remains, contact a diagnostician with an oscilloscope - he will help identify hidden faults (for example, misfires at high speeds or unstable operation of the injectors).

💡

90% of engine starting problems are related to three systems: power supply (battery, starter), fuel (pump, injectors), ignition (spark plugs, coils). Start your diagnosis with them.

FAQ: Frequently asked questions about engine starting problems

The car doesn't start the first time when it's cold, but it's fine when it's hot. What is the reason?

Most likely the culprits are:

• 🔥 Spark plugs (carbon deposits or wear).
• 🌡️ Temperature sensor (The ECU calculates the mixture incorrectly).
• 🛢️ Thick oil (in cold weather it is difficult for the starter to turn the crankshaft).
• 🔋 Weak battery (not enough current to scroll).

On diesel engines it is added fuel waxing (summer diesel fuel freezes at −10°C). The solution is to use winter fuel or add anti-gel.

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

Diagnostic sequence:

1. Check presence of spark (unscrew the spark plug, apply it to the ground and turn the starter).
2. Make sure fuel arrives into the ramp (press the spool valve on the fuel rail - gasoline should spray out).
3. Check crankshaft sensor (without its signal the ECU will not give the injection command).
4. Inspect fuses (especially those responsible for the ECU and fuel pump).

If there is no spark, the problem is coils, wires or ECU. If fuel doesn't flow, it's your fault. pump, relay or clogged filter.

The car starts the second or third time and runs fine. Is this serious?

Yes, the problem cannot be ignored. Most often this is:

• ⚡ Air leak in the intake manifold (check hoses and gaskets).
• 🔧 Worn spark plugs or wires (insulation breakdown).
• 📉 Falling fuel pressure (pressure regulator or pump is to blame).
• 🔄 Faulty phase sensor (The ECU goes into emergency mode).

Over time, the problem will worsen and the car will no longer start at all. For example, air leak leads to a lean mixture and overheating of the engine.

Is it possible to drive if the car has trouble starting?

Short-term - yes, but it is fraught with:

• 🔥 Catalyst overheating (due to rich mixture during repeated starting attempts).
• 🔋 Low battery (the starter consumes 200–400 A when scrolling).
• ⚙️ Accelerated starter wear (brushes and bendix consume resources).

If the problem is fuel system or ignition, driving is possible, but fuel consumption will increase by 15–30%, and the power will drop. If you're guilty immobilizer or ECU, the car may stall while driving.

How much do diagnostics and repairs cost?

The cost depends on the reason:

Malfunction	Repair cost (RUB)	Diagnostic cost (RUB)
Battery replacement	3,000–15,000 (depending on capacity)	Free (voltage check)
Starter repair	2,500–8,000 (replacement of brushes/bendix)	500–1 000
Cleaning injectors	1,500–4,000 (ultrasound)	1 000–1 500
Replacing the DPKV/Max air flow sensor	800–3,500 (depending on sensor model)	300–800
ECU diagnostics	1,500–5,000 (reflash)	1 000–2 000

The average cost of complex diagnostics in the service is: 1,500–3,000 rub.. Do-it-yourself repairs (for example, replacing spark plugs or cleaning the throttle) will cost 300–1,500 rub..