1985 Nissan 300ZX Cold starting

Tiny
ROB WEBSTER
  • MEMBER
  • 1985 NISSAN 300ZX
  • 6 CYL
  • 2WD
  • MANUAL
  • 200,000 MILES
I have a 1985 300zx. I have been having problems with starting the car when cold. It has been giving me trouble for years. I just did a motor swap last week. A newer 3L V6. Swaped the long block. Kept original intake and exhaust. Now my starting problem is worse. Once the engine is warm it runs excellent. Takes a act of god to get it to start when cold. Turns over just dosn't fire on all six.
Do you
have the same problem?
Yes
No
Tuesday, August 12th, 2008 AT 11:36 AM

3 Replies

Tiny
RASMATAZ
  • MEMBER
Check the fuel pressure and comeback with your readings or you can try below and see what happens when it cranks and refuses to start

Get a carb cleaner and spray into the carb or the throttle body on an EFI. Did it start and die? If not disconnect a sparkplug wire or 2 and ground it to the engine -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel problem, check the fuel pressure to rule out the fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil, distributor pick-up coil, ignition control module, cam and crank sensors-
Was this
answer
helpful?
Yes
No
Tuesday, August 12th, 2008 AT 11:55 AM
Tiny
ROB WEBSTER
  • MEMBER
Fuel preasure is good what is a noid light? I did not see crank or cam sensors. I dont think it has them. Changed motors stripped down to the long block did not see any sensors. I will check for blue spark. Fuel preasure was over 15 psi
Was this
answer
helpful?
Yes
No
Tuesday, August 12th, 2008 AT 12:47 PM
Tiny
RASMATAZ
  • MEMBER
Fuel pressure at idle should be 30psi and when accelerator is depressed should be 37psi

Noid light is what you use to check if the injector/s are pulsing-meaning getting power on and off

Let me know about the snapping blue spark-nonexistence it will never start
Was this
answer
helpful?
Yes
No
Tuesday, August 12th, 2008 AT 4:34 PM

Please login or register to post a reply.

Recommended Guides