Ok here's the problem I've been having.
When the car sits an hour or longer it cranks for like 3-4 seconds and then it would start up. (before it was 1-2 seconds). It's gotten progressively worse.. now it cranks for 4-5 seconds and then it sounds like it's catching it and it dies. The second I try to start it up again it starts instantly. Depending on the temperature outside it idles lean for 5-10 minutes (16-18 afr on the AEM Wideband) and then goes to stoich (~15 afr) after the car warms up.
I'm thinking it could be faulty injectors (changed plugs, wires recently), IAC valve or ignition coil (but would it be idling lean if it's the other two?)
Any input greatly appreciated.

 

I have that same problem. and I been trying to figure it out myself. let me know if you solve the problem.

 

Well in my case it turned out to be the fuel pressure regulator.
I recently installed a b&m to lower the idle fuel pressure. It must have been faulty or something because as soon as I put the stock one back on, the problem went away.

 

thank's man..I think I will remove my after market fuel regulator tomorrow.