ok i have a 91 da with a gsr swap it runs n stuff however there r times when it dont want to start... it cranks n try to start it but it just wont... at first i thought it was missing gas... cuz my gas needle on gage broke.... so cant tell how much i got... it wasnt that tho... when it does this it does it for a while but later it starts...
wat can it bee....

 

broken spark plug wire

 

try the main relay

 

it can be a billion things. the more info you give the easier it is to diagnose. for example, are you getting sparks? check for spark at the plug/distributor. Or is the main relay working? depending on which one you have, sodder can weaken which disconnects the main relay, making your car not stop as well. is the fuel pump working?