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Q: Car doesn't start

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While driving , my car turns off . It appears that the engine will start only when you spray carb cleaner in the engine filter conected to the throttle body . However , when you press the gas it turns off . I changed the fuel pump, fuel pressure, and spark plugs and it still doesn't work . Do you think it has something to do with the electical system or Throttle body ?

My car has 180000 miles.
My car has an automatic transmission.

If there is a check engine light on, you should check for codes first. If not, the one thing you have not checked yet is injector pulse. Injector pulse is driven by the PCM (powertrain control module) and the PCM is signaled by the crank sensor as when to fire the injector pulse. You can check for injector pulse by using a noid light and connecting it to the injector connector. With the noid light plugged in, crank the motor. The noid light should flash rapidly. If it does not, the crank sensor may be at fault.

Another diagnostic path to check uses a scanner. With the scanner connected you will want to look at the data for the crank sensor. If there is not a crank sensor signal, it is time to directly check the crank sensor.

If this doesn’t reveal any problems, the next thing to do is to check for spark. You can use a spark tester inline with the coil removed from the cylinder but plugged into the connector. The spark tester should be plugged in place of the spark plug. If your car runs when something is sprayed into the intake, this indicates you have spark. The fact that it won’t rev past idle only is simply a factor of not being able to supply the motor with enough fuel in this fashion. In other words, it would be normal for the motor to die when the accelerator is pushed when spraying something into the intake.

There are a few other things that will cause your car not to start, but they won’t allow your car to drive at all. If your car drives then turns off, then begins to drive again after a time, then the above items are the most likely causes. If your car turned off while driving and has not restarted since, you will want to check compression. If one or more cylinders are low, you may have a timing belt issue. You would need to remove the timing cover to inspect the timing marks and belt condition.

If you should require further assistance, a certified YourMechanic technician can be dispatched to your location to help inspect your non-starting vehicle.

Good luck!

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