V10 won't start when cold
 

Hi,
I tried posting this in the V10 forum, but no one replied, so I thought I'd expand my audience.
I'm having a problem with starting the V10 in my 99 E350 cube van. It refuses to start when cold unless I stick my finger in the idle air control valve and force it shut, or use starting fluid, or a combination of both. Once I do get it started, it will die if I touch the throttle, but once warmed up, it runs fine. I have replaced the IAC, the cylinder head temperature sensor, the fuel filter and fuel pump, and cleaned the MAF. My code reader shows no codes, and like I say once warmed up it will run fine and restart no problem. I'm kind of out of ideas on this one, anyone have any?


Thanks,

What signals the IAC valve to close? That is where I would be looking. Is it vacuum operated? A bad vacuum line?