Got 350z de engine
the car on cold start cranks but starts after long attempts
also running rich till warmup
changed the water temp sensor
also new fuel pump
checked also the injectors and they are working fine
any help ?

 

Any Check Engine Lights on?

Usually this is a combination of the following:

Wearing / worn out crank shaft and cam shaft position sensors (just replace all three of these with either OEM nissan or Hitachi brand only, and only purchase from a trusted source)

Clean and reset the Throttle Body

Clean the MAF sensor

Check your spark plugs to ensure they are not fouled

Make sure there are no vacuum leaks and make sure the intake is in good shape