Mike Kwon

i have 300zx turbo with hard cold start in the morning.

1. i have to crank 3 to 4 second before it finally run.
after that it starts fine in one crank.
2. or it starts fine on two trial. cold starts.

3. it has 52500 original miles.

check all the vacuum and all sensor connectors

new plug wire cap rotor fuel filter

rogerz

check operation on the air regulator right side of engine fwd of the EGR. If that checks out either ohm out or replace the CHTS. Most likely culprits. get the fsm from xenon and READ IT. the other fix is to give it a slight amount of throttle during cranking.

Mike Kwon

thanks
let me test the air regulator

zxguy1986

Chased down the same problem with my turbo. In a cold start, turn ignition on but don't start it. Wait. Dash lights up. Listen to fuel pump hum as it re-pressurizes system - for 10-12 seconds. Then turn key to start.

Also switched out old battery for new one rated for more (excess) Cold Cranking Amps (CCA). Check your battery for that rating.