Hey guys,

Have a weird problem that the dealer is having a hard time fixing. My 12 G37S Sedan 7AT, has a hard time starting/long crank when hot (engine temp hot). So, if I drive, then park, then start 90 mins later, I get a long crank that eventually gets the car started. Opposite...when cold/ambient temp in the morning, the car starts TOO quickly, hard to tell...but it doesn't crank the normal 3-4 times.

Somethings up....just started happening one day.

Any thoughts?

So far the dealer attempted fixes:
1. Run a 3-4 tanks of gas through...no better, so not bad gas.
2. Bled fuel line of air...no better.
3. Software update for my 12(???)...no better (but I'm curious what was updated)
4. Check/tighten engine grounds...no better.

Be nice...they're probably reading this.

Mike S.

 

Sounds like leaky injectors.

 

Maybe bad coolant temperature or air temperature sensor, or their connections/contacts? Perhaps one of them isn't sensing right when it is heat-soaked (that's NOT unheard of), and as a result the ecu is using wrong fuel mixture or timing for hot start. Could also be fuel pressure regulator related.