1994 Nissan 300ZX Engine idle

Hi bogey123,

Thank you for the donation.

Do you mean the idling speed is at 1700 rpm?

The car idles normally at 700 to 750 but sometimes idles higher. Intermittenly.

every problem ive delt with that has a ideling problem has to deal with the wiring harness or the TB sensor which will be the small black box on the right side of the intake plenum check your timing too, if it bogs down to 700 as you say then shoots up past 1.5 you could have misfire causing you to detonate 2 cylinders at the same time instead of all 6 going off seperatly and smoothly

When idling speed increases, the following should be checked.

1. Idle Control System. Auxiliary Air Control Valve, Fast Idle Control Device are components thay should be checked/cleaned.

2. Vacumn leaks at intake system. Check the PCV and other vacumn solenoids that might be sticking.

3. Throttle linkage operations. Cheeck cable adjustment. If there is insufficient free travel, the throttle might not be able to close fully intermittenty.