Explorer won't idle when cold.... Please help

[Firedawgy]

OK I'll keep it short and quick. My college daughters 2002 sport will not start when its cold unless you hold the gas pedal to the floor, once it starts you have to hold the idle around 2000 rmp for a min or so to get it to idle, otherwise it will shut down. What could be causing this? I also noticed that when in park, if you rev it, it hits what feels like a rev limiter around 4K rpm. I have never seen this on any other explorers I have owned. Is that normal or maybe have something to do with this. We did have the upper intake gaskets replaced last year. Please someone help, she will be bringing it down next week and I plan on working on Melvin (her nickname for it), plugs, oil, the works.

 

[James909]

The fact that you have to floor the throttle to get it to start means that the truck is flooding. It's probably caused by either a bad ECT or stuck IAC. So I would try cleaning the IAC and checking the resistance of the ECT. BrooklynBay has a list of the ECT resistances in his list of useful threads. As for revving it in park, I believe that the newer Explorers have rev limiter when in park/neutral which is probably what you're noticing. It's to keep people from doing full bore neutral drops.

 

[Firedawgy]

Thanks James, gonna try the IAC when she brings it down in a couple weeks as well as plugs, odds are they are the original plugs and its got 120K on it, though can't complain for $2100 on Ebay. Was thinking about doing a seafoam cleaning to it, any thoughts? Might help the rough idle a little. Better not let my daughter read about the neutral drops. Most kids now a days will never know what its like to do a 4500-5000 rpm neutral drop in a big block.