Yes I was a mechanic but these weren't around then. Probably something simple and might even be normal. When you turn the key it feels like it's not going to start and then it suddenly revs to 1000-1500 rpms and then dies back down to normal idle speed just when it is very cold.

 

Hey Brent, I'm gonna move this over to the V10 forum where the 6.8L experts can weigh in on your question. They eat, drink, and sleep everything V10 over there and should be able to get you squared away.

Stewart

 

OK thanks.

 

my mind first jumps to the Idle Air Control or Mass Airflow Sensor as those are the only two things i have seen cause anything close to that. could be something else but thats just off the top of my head.

 

Mine has done this since new after it has sat for a few days, and I lived in southern AZ at that time. Sometimes it does it, sometimes not, even after sitting for a couple of weeks. Just my .02 worth but I say normal.

Ken

 

I don't think it's the IAC, should not effect a cold start.
Brent, are you getting any codes?

 

No, it just doesn't start quite as fast and then suddenly revs up for a couple seconds when it's about 40* in the morning.

 

Have you had your battery load tested? I only ask because of slow start.

 

Actually, it might be the IAC getting sluggish in cold weather. They've had that problem since the mid-80s.

 

The battery is fine, the engine just hesitates like it's not going to do anything and then suddenly revs up but not always.

 

This is the closest I've come to a possible explanation but above they say it's not the iac.

 

Then they (above) probably haven't been around Fords for 25+ years and had to deal with IAC valves with cold-weather morning sickness....

You can crack the throttle 1/4 way and see if the engine starts more quickly. If it does, then it's the IAC. If it doesn't, it may be related to fuel pressure at the rail and you'll need to use a pressure gauge to investigate that.

 

You can pull the IAC, clean and reinstall to see if that makes a difference. I agree that the IAC is a likely culprit here.

 

My money lies at the IAC, had the same problem with my 2000 V10....cleaned it and hasn't done it since.

 

This thread has gone from not IAC to it is the IAC and Russ had the gut feeling to start with, so I am leaning towards the IAC...........thanks everyone.