I went ahead and unplugged the MAF sensor and started the truck cold, this time I found that the idle started about 1700 and then went back down right away. Does this symptom make it seem like its a MAF issue? can a bad sensor cause a rough Idle when warm?

 

Do you happen to know what is a normal vacuum pressure for a 4.6 D2? I ran a vacuum gauge on the intake manifold and found a steady 14.5. that seems low to me. I guess there could be a possible vacuum leak somewhere. However, I don't think 14.5 is bad enough to make the truck think it's about to stall.

 

Would it be possible for coilpacks to cause a high cold idle also?

 

Get new coil packs for peace of mind and new 8 mm wires
rock auto has the coil packs bosh ones for cheap

 

I am wondering if it has something to do with the the coolant temperature sensor as the behavior changes with heat. I will try and apply both hot and cold to the sensor and see if anything changes.

Thanks in advance

 

Has the EGR valve ever been replaced?