Why does My friends Honda Civic Ex just shut off for no reason

Question

My friend owns a 2004 Honda Civic EX .He chaged the spark plugs and the oil but he thought the spark plugs where pre-gaped he didnt check so after we was done changing the oil and spark plugs we took it for a ride the car seemed to be running great we drove around for about 10-15 mins. and he drove it like that for about a day then he had a hunch that he wasnt quite sure if they where pre-gaped so I called the part store to see if that brand was pre-gaped and the werent so we pulled them out and gaped them to specs .044 so now it runs good still but sometimes it just shuts off if like he shut it off by key what could it be?

Answer 1

Run the car on idle (neutral) and put on the emergency brake.  Then use a multimeter to measure the voltage across the battery.  If it reads less than 13.5 volts, then the diodes in the alternator are beginning to fail.  Bad alternators can cause your car to shutoff including power steering so be careful when you are driving on the highway; stay close to the emergency lane to be safe.  Replace your old alternator with a new one and make sure the voltage reading is above 13.5 volts.

If it is above 13.5 volts and still shutting down unexpectedly, inspect your sparkplug cables, distributor cap, distributor rotor, and your distributor.

Good luck!

Answer 2

check your spark plug wires

or your ignition