'07 G35 Journey sedan.

The last 3 days the cold start is not normal. It starts fine, but the idle rpm's are in the 500 range for the first few seconds then come up to a normal 1800rpm before decreasing to 650rpm. No work has been recently done other than an oil change about 3 weeks ago. Car runs normally with good power when warm. Outside temp doesn't matter. Cranking speed sounds ok.

Tom

Your spark plugs could be getting worn out, maybe. TPS could be set wrong, maybe. Fuel pressure regulator may be going bad. I know, too many maybes. Hard to make a differential diagnosis without more symptoms.

Spark plugs are brand new along with air filters. Forgot to mention this in my original post. I would expect a fuel pressure regulator to impact normal running as well which is not the case.

This issue has gone away, possibly due to replacing the ground cable.