Hi I have a 87 d21 4x4 cranks and no start

think that possibly you are running with a reduced voltage condition...magnetics are weak for example an injector may not know when to pulse exactly...my recommendation is get a brand new battery, brand new battery cables and wirebrush the area where the second cable to the block attaches~ this way your ECU will not produce errant behavior~

If you said it cranks I think your ok there.when you said fuel pump did you mean fuel pressure or relay.check your pressure.

I recently Bought an 87 Nissan d21 2.4 and would not start! So I did a couple troubleshooting! I used a good known battery to start off! I checked fuses, relays all good! I Had fuel(you can hear the pump running, hence I checked the fuel pump relay before aswell)! Fuel was there but I had no spark so I checked for spark but no spark, and I back tracked and Found one of the ICM( YOU HAVE 2 FOR INTAKE AND EXHAUST ON 2.4). After that I replaced but still no spark! So I checked my distributor and I opened it up and found my angle crank sensor melted as why it was not reading, not allowing spark to the spark plugs! So after replacing the angle crank sensor it finally started! These hard body engines are very good I love the fact its timing chain so no maintenance needed!