Hi all,

I'm having starting difficulties with my -07 ix.

It has stock injectors, stock fpr and the fpr solenoid is working.

Cold start is perfect, if I shut it down in any temp and start within 10 minutes it fires right away. If I let it sit for more than 15 minutes it will crank like 4 seconds before starting up, once it starts it has no hesitation running. After 4 hours of sitting it fires right away. Anything between 15 minutes to +3 hours it cranks for prolonged time.

I don't believe it's tune related, it has done this with oem tune and now on speed density. And like I said it's more related to sitting and not to temps. Hot start is flawless if done within 10 minutes, no matter what the CLT is after sitting it just cranks for long time before firing.

Ambient temp plays no role, it's been 0F outside and fuel rail is cold to touch but if the car has been driven within two hours the problem is there.

I've gone thru some old topics where people suspect it's vapor lock due fuel boiling in the rail but could it be after sitting few hours in sub-zero temps? Mind you the real cold start in the morning is perfect.

Any ideas what to look for? Vacuum leaks are checked, fuel injectors are checked for leaks, battery is good, BISS is adjusted. It's really annoying and I haven't found a cure from old topics.

I had an issue like this and it ended up being the MAP sensor

I would also try a different MAP sensor. They can cause all sorts of weirdness when they aren't working perfect.

How is everything now?

This the problem really the MAP sensor? My car also have got a long cranking in cold start, plus I have got worse mileage now.