Nissan Repair: 81 280 zx cranking but not turning over, line cars, process of elimination

Question
my brother has a 81 280zx non turbo it will crank up but not turn over we have replaced plugs wires mass airflow fuel filter throttle positioning switch even did the timing im getting a spark from the plugs and plenty of fuel but when you turn the key it cranks but wont completely turn over sometimes we will get kinda like a putt from it but thats about it we are going crazy please help us will owe you our lives

Answer
Hi Steven -

Please tell me how you checked the spark on the plugs. I want to ensure we are on the same page.

Also, when you say you have plenty of fuel, do you mean in the fuel tank, or are you checking volume and pressure at the fuel line?

Cars do not start for 2 reasons, no spark, or no fuel. The process of elimination is the best way to go. Find out what it is not and then it gets easier.

PLease get back to me with the info and we can go to the next step.

aloha
calvin