Dont get why car just starts when I disconnect the battery, after running fine for a while

Hi there guys I got a question to ask. For some strange reason my car has the habbit to not start at random times. I got a 93 civic si (canada) (stock engine). Ill explain you more. One day (a month ago) I was on my way to school and was going to start the car but she didnt want to. I tought it was a dead battery but i could hear the fuel pump priming and there was spark. I even called my friend for a boost. The main relay clicked three times as supposed to. Unfortunately at the time i didnt check the fuses kuz i didnt know how to. I still dont know. I was frustrated and call the mechanic. He took it for a while and said it was fine. I was surprised but didnt care.

Now yesterday I was on my way out and my car didnt wanna start again. I got pretty mad kuz it was the same thing again. It was cranking but not starting. I tried everthing i could and nothing still. I thought i had fludded so i waitted 30 min and still nothing. then I called my friend and told me to reset the ecu. I disconnected the ground for the battery for like 15 secs, connected back in and then she was running again. So i was like "O so i just needed to reset the ecu". Now today the same thing happened. I disconnected the battery again for like 15secs but still didnt want to start. Then i disconnected it for like 10 min and she started like a champ.

Does anyone know what is exactly happening here. My mechanic checked the timing belt and it was fine. I dont know what is exactly wrong with this. Seems to be something electrical.

I would appreciate some advices as winter is coming and dont want to be struggling with this in shitty weather.

Would it be a faulty ECU? If so why would it work after I reset it? I havent checked for codes either as the CEL hasnt come on besides when i start the car.

Thanks, Luis

Check to see if you have spark?

My car did this and it turned out to be a faulty ignition coil and wires

Not sure if this could be it, but when i was workin at a shop a prelude had same sorta problem. Problem was the fuel pump relay.

supra if you read a little more he says the fuel pump is priming being that it is working.......... i'd venture out onto a limb here as i hate hondas and go with injectors?

Maybe the fuel pump isn't functioning properly? I know with my race car, it would have a hard time starting, then finally start. But as soon as you went to give it gas, it would die. It turned out the fuel pump worked enough prime the engine, and get some fuel into it. But as soon as you put load on it, it died. I'm sure there is a way to check this with hondas...

FlyingBrick wrote:

Maybe the fuel pump isn't functioning properly? I know with my race car, it would have a hard time starting, then finally start. But as soon as you went to give it gas, it would die. It turned out the fuel pump worked enough prime the engine, and get some fuel into it. But as soon as you put load on it, it died. I'm sure there is a way to check this with hondas...

That is the same problem I had with my 240sx. It would prime terribly slow and idle, but once you started to accelerate it would bog cause it couldn't feed fuel quick enough to keep up.

why did your mechanic check the timing belt? so random.

is the engine turning over when you turn the key?

Oh and to reset the computer, you are suppose to disconnect the battery AND press down on the brake pedal for a few seconds to COMPLETELY discharge the system, then reconnect the battery. hope that helps

Just check to see if you have spark first ! this is a common problem when the ignition coil is going,

my car had the same problem and finally got to the point where it wouldnt start at all

thats why im asking if its even turning over.

I always see people trying to start their car and its turning and turning and turning (at a good speed) and they are like... must be the battery. like WTF?

then you have people trying to start their car and the engine isnt turning over, then they start checking to see if they have a spark or fuel etc.....again...wtf.

this is the line that confuses me

luispizarro25 wrote:

I tought it was a dead battery but i could hear the fuel pump priming and there was spark.

raboyto2 wrote:

thats why im asking if its even turning over.

I always see people trying to start their car and its turning and turning and turning (at a good speed) and they are like... must be the battery. like WTF?

then you have people trying to start their car and the engine isnt turning over, then they start checking to see if they have a spark or fuel etc.....again...wtf.

this is the line that confuses me

luispizarro25 wrote:

I tought it was a dead battery but i could hear the fuel pump priming and there was spark.

I think he means that he thought it was dead at first and then concluded it wasn't becasue of that? I don't know I didn't read the whole thread just your post.