Truck cranks but, doesnt 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 : Typically when the battery has been disconnected for an extended period and is replaced, an error code will be triggered in the ECU of the vehicle and disable the ignition system. This is done as a security feature; but tends to be a major inconvenience for car owners. The only way to resolve this issue is to have a professional mechanic complete a check engine light inspection, so they can download the stored error code, clear the code and verify that the car will start. If this is not the problem, a more in-depth inspection will need to happen.

ANSWER : Hi there, thanks for writing in. I’d be happy to help. It sounds like you should disconnect the connector to the fuel pump and inspect it for any signs of getting hot. The female connections may be too loose on the fuel pump and lose contact after running and getting hot. If there are indeed any signs of problems, then I’d suggest replacing connector and adding dielectric lube to pins before installation. This should solve the problem, but if you continue to experience issues, feel free to reach out to us for help again.

ANSWER : It is very likely that you have a powertrain control module failure. This can happen often on many GM vehicles. I would recommend having the powertrain control module tested and replaced as necessary in order to resolve this issue. After the powertrain control module is replaced, a reflash procedure will be required so that the vehicle can relearn all of its primary engine data. Once the reflash is completed, your vehicle should no longer have this issue.

ANSWER : Check the exhaust system for any leaks before the oxygen sensors. This can contribute to having more oxygen in the exhaust stream causing the sensors to register a false reading. If there is no leaks in the exhaust, then check the engine for any vacuum leaks. Look at all of the vacuum lines, the intake gaskets, and the brake booster. A vacuum leak will cause the engine idle to accelerate fast and also cause the engine to stall when the computer brings the idle down. If you need further assistance with your engine stalling, then seek out a professional, such as one from Your Mechanic, to help you.

ANSWER : Gasoline is generally not usable after 3 to 6 months. If gasoline has been stored in the vehicle for a lengthy time, the problem is likely that there is just simply nothing to combust. The volatile components in the gas have evaporated and other compounds in the gas have turned to varnish and gum, possibly plugging up the carburetor. If the tank was drained though and the fuel in the fuel system is fresh, please simply request a no start diagnostic and the responding certified mechanic will pinpoint the cause of the no start condition. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

ANSWER : I suspect your ECT (Engine Coolant Temperature) sensor is stuck at -40 degrees. When this occurs, the PCM dumps as much fuel into the motor as it can because it believes the outside temperature is -40 degrees Fahrenheit. You will need to connect a scanner to be sure.

You can do what is known as a clear flood. Push the gas pedal all the way to the floor and hold it there while you crank the motor. This is a really good diagnostic test for a flooded condition such as you might have. You will most likely need to crank the motor for an extended period of time and when it does begin to start, you will need to feather the throttle to keep in running until the excess fuel clears out. It may smoke a lot as well, so if your parked in a garage, I would move it out if you can.

It is possible the cylinders have been washed with fuel so much that compression is now too low to run the motor. This would seem to be improbable, but this actually occurs more often than most are aware of. If this is the case, you will need to squirt oil into the cylinder to help them build up compression. The rings actually need some oil around them to help them seal. This is part of the normal operation of an internal combustion motor.

A flooded condition can and often is difficult to deal with. Leaking fuel injectors or a broken fuel pressure regulator diaphragm can do the same. Remove a spark plug on the side that the smoke is coming from and see if the spark plug is wet.

If you should need further help with this, consider YourMechanic, as one of our mobile technicians can come to your home and diagnose your starting problem firsthand.

Good luck!

ANSWER : Hey there thanks for writing in about your 1998 Honda Accord. This could be a few things. A faulty ignition switch, a failing crank sensor, or possibly other faulty sensors could be the cause. To have this taken care of, consider having a certified technician, such as one from YourMechanic, come to your car’s location to diagnose and repair the hard start issue.