1985 Nissan 300ZX Cold starting

1985 NISSAN 300ZX
200,000 MILES • 6 CYL • 2WD • MANUAL
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ROB WEBSTER
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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.
Aug 12, 2008 at 11:36 AM
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RASMATAZ
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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-
Aug 12, 2008 at 11:55 AM
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ROB WEBSTER
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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
Aug 12, 2008 at 12:47 PM
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RASMATAZ
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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
Aug 12, 2008 at 4:34 PM