93 Accord D4 light flashing , WONT START

Okay , the D4 light in the dash is not always flashing when I get in the car , but when it is AND the check engine light is on , the car won't start.
It will turn over
It will crank
BUT it won't start
sometimes the check engine light will go off , and it MIGHT start if I give it some gas, If i'm lucky. Then I have to change the gears while i'm driving , and the light is flashing , as if i'm driving a manuel.
It doesn't always do this, but lately the light is flashing everymorning. and takes forever to go off..
I changed the distributor cap a couple nights ago and it was working fine , but the light came back ..

Please help me , i think it's the fuel filter...  

Change your fuel filter and if you can do a pressure test on ur fuel system but make sure the car it at normal operating temp,to make sure your fuel pump isn't going bad