Car wouldn’t start in cold weather

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 : Hi there. Given the description of not being able to start your vehicle, when it is cold and jump starting the vehicle without any problem. This leads me to believe the battery does not have enough cold cranking amp capacity. The engine needs to turn over fast enough to start. This may be nothing more than a weak battery. I recommend having this confirmed by a certified technician from YourMechanic.

ANSWER : It’s clear that your battery is dead. If you want to try charging it, you need to put it on a slow charge for 12 hours or more, but I suspect even then it won’t do the job. It was probably marginal for a while and then a few nights in the deep cold were enough to finish it off. When you get the battery changed, you will want to have the charging system tested to be sure that it is OK, but since you can run after a jump, I expect you’ll find that it is all right. Be sure you have a good battery in the car before you test the charging system. If you don’t you might get a false reading. As for jump starting the car. I strongly advise against having anyone besides a professional do that. I have just finished fielding some questions for people who have done a lot of damage to their cars by hooking up the jumper cables backwards, even for a moment. The car’s electronics are very sensitive to the voltage surges that come with jump starting a car. To conveniently have your battery replaced, you can contact Your Mechanic, they can send a technician to your home or office to replace your battery and see what else might need attention.

ANSWER : Hi there. The cold weather timer is a great feature to have, but you can adjust the time for the auto start to stay on for. I recommend setting the timer for 20 minutes to allow the engine to warm up. The hardest thing to do on an engine is start it up and shut it off before it warms up. This will gel up the engine oil and causing the engine to fail due to lack of engine oil. If you need further assistance with your auto start system, then seek out a professional, such as one from Your Mechanic, to help you.

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 : Hey there. This may also be caused by what is called the fuel pressure regulator. This is a unit that helps to maintain the fuel pressure at the proper level. When this is not working properly, the fuel pump may be pumping properly, but the fuel may not arrive at the fuel injectors at the proper psi. When this happens, this can cause a lean fuel condition which may cause the car to hesitate, misfire, or stall. If you would like to have an expert pinpoint the issue, a certified professional from YourMechanic can come to your car’s location to inspect the hard start problem and confirm which repairs are needed.

ANSWER : A number of things can effect a vehicle’s ability to start in cold weather. The battery can have enough power to to turn on lights and other accessories, but not have enough power to crank the engine. The engine needs more power to turn over when cold. electronic issues can also cause no start issues. The engine also needs more fuel to start in cold weather. If for example, the coolant temperature, or ambient temperature/barometric pressure sensors are faulty, they may not signal the engine control unit that it is in fact cold out and the engine requires more fuel to start, starting issues will arise.

Have the battery load tested to make sure it is supplying the correct cold cranking amperage. If the battery is good, have a certified technician look into the no start condition to isolate the exact cause.

ANSWER : Hi. There is a couple of things that could be wrong here. The battery or alternator that was just installed could be defective. Theses parts need to be tested for proper operation. There also could be a fuse, fusible link, or wiring for the battery or charging system that is blown or broken causing the battery light to come on.

The codes that you have will cause the car to shut down, run rough, or not start at all. The crankshaft sensor and camshaft sensor should be replaced. I suggest having a certified technician from YourMechanic come diagnose the charging system and check engine codes to help you proceed with correct repairs.