Prolonged scrolling by the starter before successful engine start-up most often indicates a drop in pressure in the fuel ramp or a malfunction of the crankshaft position sensor. If The car starts the second time.This means that the engine control system does not receive the correct data or create the necessary mixture for ignition. Ignoring this symptom can lead to a complete failure to start in the cold or a critical discharge of the battery.
In modern fuel injection systems, the ignition delay is often caused by pressure leakage through leaky injectors, causing gasoline to drain into the cylinders or back into the tank. Electronic control unit ECU At the first attempt of the launch, the command is given for injection, counting on the residual pressure, which is not provided. Only after re-pumping the pump creates conditions for normal operation of the motor.
Diagnosis should begin with checking the state of spark plugs, since the soak or increased gap of the electrodes does not allow the spark to penetrate the compressed mixture the first time. Wet from gasoline candles talk about the re-enrichment of the mixture, and dry plaque - about problems with the supply of fuel. In any case, regular engine start after several failed attempts requires immediate intervention of a specialist.
Problems with fuel supply system
The most common reason why the machine does not start immediately is a violation of the tightness of the fuel system or wear of the pump elements. When the engine is dead, the residual pressure must remain in the line, allowing instantaneously to supply gasoline to the injectors at the next start. If fuel-valve or the pump's return valve does not hold the pressure, the fuel drains, and the pump takes time to re-inflate the system.
Clogged fuel filters also create flow resistance, which is why the pressure in the ramp does not have time to reach operating values when the starter first scrolles. Owners of cars with high mileage often face pollution of the gas pump grid, which leads to "starvation" of the engine at times of peak loads at start-up. Replacing a thin cleaning filter is a must-have procedure when looking for reasons for poor start-up.
- 🔹 Wear of the gas pump return valve results in the fuel draining into the tank.
- 🔹 The leakiness of the fuel injectors causes a drop in pressure in the ramp.
- 🔹 A clogged fuel filter limits the throughput of the highway.
⚠️ Warning: Prolonged starter operation during start attempts can lead to overheating of the electric motor and battery discharge below critical level.
Ignition system malfunction
A weak spark or lack of it at some point in the crankshaft rotation is the second most common cause of launch problems. If The car starts the second time.It is possible that the ignition coil or module has an insulation breakdown that only manifests itself when heated or vibrating. In the cold season, condensate in candle wells can create a conductive layer that leads the spark to the mass.
High-voltage wires with expired service life lose the ability to transmit the necessary charge, especially in wet weather. Microcracks in isolation become noticeable only in the dark as a glow, but during the day they manifest themselves only by unstable start. Checking the resistance of the wires and visual inspection for damage often reveals a hidden defect.
Incorrectly exposed gap on spark plugs violates the process of spark formation. Too much gap requires an increased breakdown voltage that the old coil may not provide the first time. Too small a gap leads to poor ignition of the mixture and the need to try again.
Failures in the operation of sensors and electronics
The electronic engine control unit relies on sensor readings to calculate the moment of injection and spark formation. If crank-point (DPC) is contaminated or has a damaged winding, it may not immediately emit a synchronizing signal at start. ECU in this mode does not know in what position the pistons are, and does not give a command to inject fuel.
The sensor of mass air flow (MMRV) in case of contamination of the working area of platinum transmits an understated reading about the amount of incoming air. The mixture turns out to be too rich, the candles flood, and the engine stalls or does not start. After a second attempt, when some of the gasoline is blown out or burned, the mixture is normalized and the engine starts to work.
Temperature sensor and cold start
The coolant sensor (CFS) plays a critical role when starting a cold engine. If it shows the wrong temperature (for example, that the engine is hot, although it is cold outside), the ECU will not enrich the mixture. As a result, the gasoline does not evaporate, and the car starts only after several attempts, when the cylinders get enough fuel.
Errors in the control unit software or failures in the onboard network can also cause delays. Short-term voltage surges during the starter operation are able to "hang" the controller, requiring re-ignition to reset the error and normal initialization of the systems.
Mechanical problems of the engine
Reduced compression in cylinders is a serious mechanical reason why motor It may not be started on the first attempt. Wear of piston rings or charred valves leads to the fact that when scrolling with a starter, sufficient pressure and temperature are not created to ignite the mixture. In the second attempt, when more fuel and oil enter the cylinder, the tightness is temporarily improved.
Faults in the gas distribution system, such as a stretched GRM belt or knocked phases, change the opening moments of the valves. This disrupts the process of purging cylinders and filling them with fresh mixture. If the GRM tags are knocked down even on one tooth, the start will become difficult, and the engine operation will be unstable.
| Symptoms. | Probable cause | Method of diagnosis |
|---|---|---|
| Start only with 3-4 times | Compression fall | Compressometer measurement |
| Launch after a long downtime | Fuel drain to the tank | Pressure measurement at the ramp |
| Unstable launch into the cold | Weak battery/candles | Testing voltage/claim |
| Launch with cotton | Phase downs of the GRM | Checking the GRM tags |
Effects of low temperatures and operating conditions
In winter, the viscosity of the motor oil increases, which creates additional resistance to the rotation of the crankshaft. It is more difficult for a starter to spin the engine to the necessary start speeds, and from the first time the system may not have time to generate a spark at the right moment. Using oil with inappropriate viscosity aggravates the situation.
Condensation in the exhaust system or ice crust in the silencer creates backpressure, preventing the exhaust gases from leaving. The engine is “choked” by combustion products, and the fresh mixture cannot enter the cylinders in the desired volume. After the first unsuccessful attempt, some of the ice can melt or shift, allowing the engine to start.
Use the Quick Start spray (ether) only in extreme cases and strictly according to the instructions. Excess ether can damage sensors and wash the oil film off the cylinders.
Fuel quality also plays a role: in winter, gasoline can contain water that freezes in the filter or fuel lines. Ice crystals block the fuel, and after thawing in a warm garage, the problem disappears, creating the illusion of an accidental malfunction.
Diagnostics and algorithm of fault search
To determine the exact reason why The car starts the second time.It is necessary to act consistently, excluding simple options. You should start with a visual inspection and check of the levels of technical fluids, then proceed to the electrician and fuel supply system. Using a diagnostic scanner will allow you to read the error codes stored in the ECU memory, even if the Check Engine light bulb does not burn.
First of all, check the state of the battery and the quality of contacts at the terminals. The oxidation of contacts creates high resistance, which is why the starter spins sluggishly, and the spark turns out to be weak. Cleaning the terminals and checking the voltage under load often solves the problem instantly.
☑️ Primary Startup Diagnostics
If the electrician is in order, it is necessary to measure the pressure in the fuel ramp using a pressure gauge. The pressure should be kept for a long time after the ignition is turned off. A rapid drop in pressure will indicate a faulty pressure regulator or "current" injectors.
Prevention and service recommendations
Regular maintenance is the best way to prevent startup problems. Timely replacement of spark plugs, fuel and air filters provides optimal conditions for the engine. Do not save on consumables, as their cost is incommensurable with the possible repair of the starter or catalyst.
Using quality fuel from proven suppliers minimizes the risk of nozzle contamination and the formation of deposits in the combustion chamber. Periodic use of quality fuel system cleaners helps keep the injector clean and prevents valves from sticking.
Key point: If the launch issue has come up abruptly, remember what work has been done recently. Often the reason lies in a poorly swirled terminal or a forgotten connector after maintenance.
It is important to monitor the condition of belts and hoses, especially in the underhood space. Cracks in the intake system pipes can lead to the sucking of unaccounted air, which impoverishes the mixture and makes it difficult to start. The tightness of the intake tract is the key to stable engine operation in all modes.
Why does the car start the second time in the morning?
Morning start problems are most often associated with a drop in pressure in the fuel line overnight or condensation in the system. It is also possible oxidation of contacts, which manifests itself after night parking at temperature changes.
Could bad gasoline be the reason for a long run?
Yes, low octane or water in the fuel disrupts the combustion process. The engine can catch, but immediately stop, requiring a second attempt to stabilize the work.
Is it dangerous to spin a starter for a long time?
Yes, this leads to overheating of the starter windings, accelerated wear of the bendix and deep discharge of the battery, which reduces its life.
How does the temperature sensor affect the launch?
A faulty sensor may tell the ECU the wrong engine temperature. If he thinks the engine is hot, he will not give a command to enrich the mixture, and the cold engine will not start.