98 ford windstar lx

Most likely is the EGR system, but to be sure; check the codes from your Windstar's computer; If you see the light "Check Engine" on; an scanner will help you to get the right codes and find the problem. The Exhaust Gas Recirculation (EGR) work in certain times, according the pressure and temperature, that's why sometimes runs great and sometimes bad. I hope this helps, take care.

Has the automatic transmission fluid and filter been changed. A flush and change is worth a try.

Is the check engine light on ?
Yes the speed sensor could cause transmission problems.

1995 windstar., 3.8 eng. Cut off after being stop awhile , slow get up to speed, new & new plugs installed.

Sounds like the solenoids are not working correctly in your transmission. May need to be rebuilt. Check with your local transmission shop about this problem.

i would try a compression test on all cyls and compare readings, sounds like something internal

change the fluid and filter to ensure oil flow inside the transmission, if the problem persists, check and adjust the kickdown cable, hope this helps, let me know.

Try replacing the fuel filter also Has it had a tune up? they need to have the plugs replaced at 100,000 if the fuel filter does not work then the most probable cause is the fuel pump is losing pressure when hot. The pump warms up and the check valve fails to close all the way allowing a now fuel or fuel starvation.

spark plugs tune up, egr valve open or not fully closed, throtle position sensor, timing.

there are too many reasons...

it could be fuel pump,, it could be ignition coil overheating, it could be the computer itself...

you need two things for the engine to run,

1 is gas
2nd is ignition,,

with these two misfiring or your loosing one of them, it will stall...

i hope i was able to give you some thoughts....

drcool