1990 2+2 300zx issues

IIRC, the DRL on the early Z32 is one of the few series circuits in the entire car. If one light is out, the other one will not turn on. If the car is showing your condition then it could mean that the car is a US car of some kind that doesn’t have DRL stock or someone has bypassed the DRL circuit originally with a DRL unit from Canadian tire or some thing like that. I’m not sure how the later years of the Z32 integrate DRL and if it’s using the same styled circuit. Any details about the car? Did you get it from the States?

I had the same problem with my car when it was NA. I fought for a year to find the problem.

  • Car would start up fine when the engine was cold.
  • Car would take a long time to start when it was warm if it was previously sitting for an hour or more.
  • If you shut the car down when it’s warm and immediately start it back up again the problem did not exist.

It’s a really hard problem to find because it is an intermittent problem. I changed a lot of things.

First I changed

  • Spark Plugs
  • Fuel Filter
  • Cleaned my HKS Air Filter
  • Oil was regular
    That didn’t fix the problem so I
  • Changed the CTS (Coolant Temperature Sensor)
  • Changed the PTU (Power Transistor Unit)
  • Changed the CAS (Crank Angle Sensor)
  • Changed the FPC (Fuel Pump Computer)
    That still didn’t fix the problem but by the end of it I had a JDM twinturbo engine to put in and that didn’t have any problems, so that’s as far as diagnostics went in one year.

Funny enough, about two months ago I tore appart the stock NA motor that was in my car and noticed that when I pulled off the heads, the back two cylinders were flaking with carbon buildup. Then I immediately remembered the problem that I had, but I’m not sure how they tie into together.

What have you changed so far to try and correct the problem?