I have a 1990 civic ef i bought a year ago and i have a problem, when i turn on the car, black smoke comes out of the exhaust? what could it be?maybe a sensor? I don't know please help out? I will appriciate it.

 

burning oil? old gas? more info?

 

the engine is totally rebuild. it could't be burning oil.
they told me it could be a sensor? what do you think? reply back thanks

 

has the car been sitting for a long time? any other problems with running?

 

its probably fryed rings. do a compression test.

 

it was sitting for a while, for like about maybe 6 months. the rpms are also low and also when you shift to second gear it kind of chokes.

 

after 6 months of sitting we rebuild the engine completly. i don't think it could be the rings. do you think it could the timing belt that is not put on time. what do you think?

 

check your fuel system. if you are using the old gas, drain it and flush the fuel lines. also get a new fuel filter. i may be wrong, but it doesnt sound like timing, but check it anyway... its not that hard. look for the up arrows on the underdrive pulley and timing gear to match up