Ok everyone i have a issue with my windstar. it has the 3.8l engine when running down the highway its smooth and fairly quiet. a few months ago i was having this really bad surging issue and thru some testing and head scratching i discovered the issue and an unrelated issue which i fixed. the issue causing the surging was a missing clip that holds the arm for one of the imrc's so i put new clips on and that solved that problem. the other thing i discovered was the lower intake gaskets were leaking a small amount of coolant into some of the cylinders causing white smoke. I replaced the lower intake gaskets, the upper plenum gaskets, throttle body gasket, isolator grommets, and cleaned the egr ports. assembled everything and the van ran great for a week or two.
then the van started surging at idle and dying at lights. checked for vacuum leaks and found none, did some more checking and ended up replacing the iacv and cleaned the maf sensor. this helped for a few days but now it's back.
This van keeps doing this intermittent surging, and sometimes it will not idle at all and die. but will restart and be fine. so to recap I'll list all parts that have been replaced in the past 6 months. upstream o2's, all gaskets in intake assembly, iacv, plugs, wires, fuel pressure regulator, pcv, checked and verified tps sensor is ok, air filter, I just purchased a fuel filter and will install that soon, also i am going to test the maf to verify voltages and signal wires. i really need to get this fixed i am tired of dropping cash into this thing. if i cannot figure this out i will prob sell it. my wife and kids ride in this all the time and i need it to be reliable.

 

ok so i just got done testing the maf and as far as i can tell it is all within specs and operating as it should.
Idle@temp-0.95vdc
1500@temp-1.40vdc
2000@temp-1.63vdc
return to idle@temp-0.95vdc
and just for kicks 2500@temp-1.84vdc
the ground circuits checked out ok as well. the voltage would rise by apprx .10 incriments from idle to around 1500 then from there it would rise pretty smoothly in smaller increments.