Why does my car struggle to start every 4th to 5th time?

ANSWER : It sounds like your starting issues may be linked to a problem with air metering or fuel delivery. A clogged or malfunctioning idle air control valve may show some of the same symptoms you are describing. The idle air control valve can be stuck in a cold start position which may work well if the car has been sitting a few hours, but as the engine warms up there must be a regulation in airflow. Consider hiring an experienced technician like one from YourMechanic who can come out for a closer look at your hard start situation and offer a more personal diagnosis.

ANSWER : The issue you are having is probably due to an intermittent fault in the starter motor itself or a deficiency in the starter electrical circuit, for example a large voltage drop due to a poor ground or a high resistance connection. These issues can be readily diagnosed and resolved on a mobile basis if you request a hard starting diagnostic. If you request that diagnostic, the responding certified mechanic will get this resolved for you promptly. Based on Toyota’s Factory Service Manual, the battery should not be disconnected if the vehicle engine is running. The battery acts as a large resistive voltage sink and consequently taking the battery out of the circuit, while the alternator is still running, can create a voltage spike on the car’s electrical system which is not good for voltage sensitive components such as the engine computer. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

ANSWER : There are reports that the replacement alternators will not communicate with the engine computer and will not charge correctly. I recommend using only the manufacturer approved replacement part. It can be new or remanufactured but approved for use in the vehicle. Some lower cost alternators on the aftermarket will have charging problems since they will not communicate with the ECM on the vehicle and will stop charging.

ANSWER : If your battery is weak or has bad connections to the battery, then you may have problems starting the vehicle intermittently. This is due to low voltage to the starter which is taking all the power, while the electronic ignition and the electric fuel pump get cut short. This will cause the vehicle not to start.

You may think the vehicle is turning over okay, but the starter is taking in all of the power just to turn over the motor. You should get the battery and it’s cables checked, as well as the charging system, for any problems by a qualified mechanic so they can diagnose the problem and do any repairs needed to prevent this problem in the future.

ANSWER : Hi there. It sounds like it could be the starter. However, the switch is definitely a possibility. If you hear a clicking sound, then the switch is operating properly. Are there any messages on the combination meter? If so, that’s good place to start; especially if the key battery has discharged and not being recognized by the smart system. The starter could also be at fault. It’s not uncommon for a starter to fail, even in today’s cars. The clicking noise you are hearing could be the starter trying to engage, but cannot. This could be a worn/faulty starter or it could be as simple as a worn/failed battery. Have the battery tested with a digital battery tester that provides current voltage, cold cranking amps, and state of health. If the battery is healthy and only discharged, have the alternator tested for proper voltage and amperage during both idle and under load. I suggest having a qualified technician perform an inspection to avoid replacing unnecessary parts. Your Mechanic has several available technicians that can assist you with a car does not start inspection.

ANSWER : Your MAP sensor is an important input for your computer. It helps determine the load on the engine to calculate the correct amount of fuel to inject. It sometimes takes a few seconds for the vehicle to realize that the sensor is not producing a good signal.

At that point, it will use other methods to determine the fuel rate, such as pre-programmed fuel maps, throttle position, etc. I would suggest replacing the MAP sensor and retesting. If you would like to have it checked first, a certified technician from YourMechanic will be able to scan your vehicle and test components to determine the root cause of your starting issue before making a repair.

ANSWER : Hi there:

Sometimes when you have problems starting an engine initially it is caused by a restriction in fuel flow; caused either by clogged fuel injectors or the throttle body that needs to be cleaned. Once the fuel starts to flow and engine warms up, it’s much easier to start. However, it could also be an air filter, EGR valve or other components that causes this issue as well, which is why it’s best to have a professional mobile mechanic complete a car is hard to start inspection so they can pinpoint the source of this issue.

ANSWER : Of course, don’t switch gears without being fully stopped, unless your Owner’s Manual or the manufacturer has alternative advice. However, the gear shift issue has no relation to the no-start problem you are describing. Inasmuch as you only have 6,000 miles on the car, the "constant on and off" that you believe has occurred is meaningless in comparison to the expected total vehicle service life. That is, assume what you perceive as "constant on and off", during merely 6,000 miles, might be equivalent to using the car "normally" for three years. A new car should be trouble free for at least 5 years, unless there is a defect, so your "constant on and off" is not a causal factor for any fault on the vehicle. What you might have is a defect in the ignition switch, or perhaps the immobilizer system, but if the problem is not in the switch itself, clearly there is an electrical problem.

If your vehicle is under warranty, by law the dealer MUST repair the issue you are describing within a prescribed time frame and number of "attempts", otherwise the dealer will run afoul of Federal and state Lemon Laws that give you very specific rights, and recourse (contact an Attorney; we are Mechanics, NOT attorneys). Consequently, if the vehicle is still under warranty, to save yourself money do be sure to seek a resolution from the dealer. If the vehicle is not under warranty, obviously a certified Mechanic from YourMechanic could identify the electrical fault and resolve this for you. If you want to go that route, please simply request a no start diagnostic -electrical system and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.