Hi All,
Truck: 2001 V10 4x4 F350, 205k miles

I've owned the truck for almost a year, and have had this issue since I've owned it. In the mornings when it is cold, the truck starts/fires right up great. Once I put into drive, the idle drops a bit, is a little rough and wants to stall out. It has stalled about 3 times. Once I drive down the block, it seems to be fine. It feels light a small vacuum leak, but I have a hard time believing that since the symptoms go away so quickly.

What I've done:
Replaced IAC Valve (Motorcraft)
Replaced PCV Hose & 90Deg connector (Motorcraft)
Replaced Fuel Filter (Motorcraft)
Replaced all Spark Plugs (Motorcraft), the COP's appear to be newer and replaced by PO
Cleaned MAF, Inspected Plastic Intake Tube and connections for vacuum leaks
Plugged off Vacuum solenoid that goes down to front hubs (Tubes were gone completely, thought this would fix it, but nope).

I'm wondering if it is some sort of temperature sensor which might be off? Is there an ohm reading chart I can use to test the ECT?

Thanks for any help you can provide!

 

Symptoms are of a vacuum leak or a sluggish IAC valve. For example, might be an intake manifold leaking that seals up once it warms. I doubt it's any sensor.

Check for an EGR or EVAP purge valve stuck open (if equipped, check).

Measure your fuel pressure with a gauge to see if you have a "lazy" fuel pump.

 

Press on the gas pedal slightly, maybe 1/4" or so, on your next cold start. See if it still does it.

Like above, could be fuel pressure not coming up fast enough.

 

Thanks for the replies.

Just to reiterate it only happens once I go into Drive or Reverse.

Cold start idle is fine when in Park or Neutral. As soon as I put into gear is when I have the issue. So, if I put into D and press gas, it takes off and feels OK, but still it stumbles off the line a bit until I start really going.

 

What are the engine RPM's in P or N compared to the drop you see when shifting to D or R ?

And have you checked the fuel pressure?

 

Just checked this morning and once it starts up and the RPM settles down in Park, it is about 1200 RPM. Once in drive it goes down to about 800 RPM but isn't steady and dips down to about 600 RPM.

 

You need something like forscan or torque that can read misfire counts etc. Without it you are taking a shot in the dark