i just swapped a 91 b18a1 motor in my 91 civic si and it wont start up. When i try to start it up, i could hear the motor cranking. Would it be soemthin wrong with the fuel, or not enough spark? I really need help and if you can give me suggestions on how to fix the problem that would help alot.

 

Are you getting power, if so. check your for power on your ignition harness. The car is a 91. The harness is old.

 

need more info, do some checks, check for fuel, check for spark, check firing order etc...

 

replace the harness. Look at you nears honda junkyard for a ignition harness.

 

no actually, unless you have broken conectors you will not need a new harness. besides, every other harness will be from a 91 aswell.

To the OP- when you turn the key to on, listen for the fuel pump to prime, it will be like a humming for 3 seconds, then it will stop. if you hear it, have a friend spray some carb cleaner into the throttle body and if it starts up you arent getting fuel or power to the injectors- causes would be fuel filter, cloged injectors or no power to the injectors-check connections.

to the spark- If you have any spark coming out of the plugs, then its enough to fire the motor. if no power out of the plug wires back track with your test light to find where you loose power.

 

it might be your main relay, that controls alot of things, it can make it so ur car wont start, give enough gas to injectors ect ect.

 

im on the same problem i think my fuel pump is shot!

 

if you dont have power or hear the fuel pump, i would check into that first.