Will not start

ANSWER : Hello. Thank you for writing in. There are several reasons your vehicle may only start when jump starting. The first and most common is a build up of resistance that is causing you to need a boost of voltage to get the engine started. This may be due to poor battery cables, a bad ground connection, a poor starter solenoid, and a couple of other issues. The first thing you want to do is perform a visual inspection of the starting system. Make sure there is no corrosion build up in the battery cables. You can also check the resistance across these wires and make sure you have a solid connection between components. You then want to make sure the starter solenoid is doing its job. It is responsible for taking the small amount of electricity sent by the ignition and turning it into a huge electrical charge that is strong enough to push over the engine with the help of some gear ratios in its favor. Do some more testing, and stick to the basics before assuming its something seriously complicated.

ANSWER : Hi there. There could be two problems here. It is possible that your battery is bad and will not take a charge from your alternator while driving. In that case every time you shut your car off you will not have enough juice to start it again. Inspect your battery – it should have at least 12.5 to 13 volts to start your car, if it doesn’t you will need to replace the battery. The second problem could be that your alternator is bad and not charging your battery, in this case you will need to replace your alternator. Both the battery and the alternator can be tested in your car. If you would like to have the car checked for you, a certified professional from YourMechanic can come to your car’s location to diagnose the starting problem and proceed with repairs.

ANSWER : Hi There,
The idle air control valve is a small valve on the engine’s intake system that reads the air intake as it comes into the motor. This is controlled by the car’s ECM which uses this information to make adjustments to the air/fuel ratio depending on various inputs such as outside air temperature, intake air temperature, load and various other things. As you accelerate, your car’s engine is receiving a much higher dose of fuel than when at idle and conversely, when you let off the gas pedal, there is a sudden change in this fuel supply as a result of your foot letting off the pedal. When this happens, the job of the idle air control valve is to bring this deceleration down to a slow and smooth idle rather than suddenly cutting off the fuel supply causing the motor to die. When the idle air control valve is not working properly, this cause a disruption in this process resulting in the engine not being able to idle properly. I would recommend having a professional come to your location to diagnose and inspect your vehicle.

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 : Hi there:

Without being there to inspect your vehicle, or having information about what type of car, truck or SUV you own, it’s very hard for us to give you some advice. You might want to have a professional mobile mechanic complete a car is hard to start inspection; so they can come to your location and determine why your vehicle is having these issues.

ANSWER : As you may know when jump starting the car, the battery power provided is being supplied form the other car you are using to jump your car with. If the car does not start following the jump, this would suggest your battery may be dead and needs to be replaced. If the battery was last replaced in 9/2012, it is most likely time for a new battery as that is a decent amount of life for a battery.

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. If you have not replaced your EGR valve, mass air flow sensor or the TPS on your Blazer, you might want to start with these repairs. It is also possible that the throttle body itself is damaged, especially if you’re able to start it on fluid. If you want to avoid chasing parts and repairs, the best solution may be to have a professional mobile mechanic come to your location and complete a car is hard to start inspection.