(2000 Windstar 3.8 170k)
New O2 sensors.
P0171/P0174 issue fixed.
2 months old spark plugs.
New Cables.
K&N filter.

When I start cold engine it is fine. Hard acceleration is fine too. But when I'm on cruising speed and my foot barely touching accelerator (RPMs are around 2k) it's then I got a misfire. I can stop it by pressing accelerator harder. I noticed that it happens mostly when it's wet outside but on dry and worm day it's fine. Hmmm.....did you ever run so low on fuel that your car chokes - thats exactly how it feels. I checked a sperkplugs and they are in great condition.

Another problem and this problem has been with me since my first Windstar 98. (I dynamically leased about 3 Windstars. Plus my own.) The problem is when I star the car worm it starts to chock so RPMs jump up to 1k and back to 600 it happens until I rev the engine a bit and then it stops. My 2000 Windstar doesn't stall and not even trying to do so but ALL my old Windstars stalled. Sometimes they did in on a corner of some busy street. Didnt' really care about that on leased cars but since I got my own I do.

Thanx for your help.

Do you have an oiled K&N by chance? If so, odds are you have oil/dirt carry-over onto the MAF sensor. Once warm, that will throw your fuel trim way off and cause the concerns you describe. You can remove the MAF and spray the elements with spray electronics cleaner.

Joel

I cleaned everything. It is the same thing. Tested and cleaned Idle Valve.
What else it could be TPS? Fuel Filter? bad coil pack?