Stalls in gear - 1990 Ford F250

Check your intake tube for a leak , if you unplug the Maf and then start it does it stall when you put it in gear ?

One of the most common failures that can cause this problem that I have seen before is the Torque converter solenoid (TCC solenoid). This solenoid can stay stuck on and cause the torque converter to stay locked up, this will cause the vehicle to stall whenever it is put into gear. The vehicle will start and run fine in park or neutral but will stall out as soon as it is put into gear. This is the most common failure that can cause this.
Also a malfunctioning idle air control valve can cause this, if the valve isn't moving or responding to bump up the idle when put in gear it may cause the vehicle to stall out, the computer commands this valve to allow more air in to bump up the idle to compensate the load on theenginewhen put in gear, if it isn't moving or isnt moving fast enough the idle may be too low and could cause the engine to stall out.Have also seen bad crankshaft position sensor cause this ,as well as mass airflow sensor's ,TPS - throttle position sensor's . Your best bet , take it to a qualified repair an have it diagnosed . No guess work .

Internal transmission breakage has stuck the thing in 3rd gear. Stalls when putting in other gears because transmission is then being put into 2 gears at once. Better look into getting another transmission of having the current unit overhauled and repaired.

Possible torque converter clutch issue. Is the check engine light on? If so, have it scanned for transmission codes. If the torque converter clutch is locked up when it isn't supposed to be, the vehicle will stall. Another thing to check is for coking on the throttle plate. Remove the hose that goes from the air filter box to the throttle assembly and look inside the throttle bore to see if it is dirty/black. If so, use carb cleaner and a toothbrush to clean while holding throttle plate open and remove as much carbon deposits as possible. This can affect minimum idle airflow and also cause a stall

You may have a problem with the idle control. What are your RPGs showing when you put it in gear?

engine stalls.
are 99% failure to do tuneups? every 60k miles ,the least.
no engine stated. there are more than one opted.

can not help on zero engine posts.

it sounds like a crank sensor if the vehicle stalls in any gear or when cold its most likely a crank sensor. located near the bottom of the engine. there almost always behind the balancer pully for the crank shaft

my ford winstar vav stalls when you put it in drive will idol all day just find

If the car does not have any other drivability problems then I would suspect a transmission torque converter problem which would make it stall with a slight ****. Does it stall coming to a stop before it has shifted to higher gears. If it stalls while in 2nd or 1st gear then it is not the converter.

Some possible causes could be:

Vacuum leaks cause an engine to run lean witch can cause the vehicle to stall when put into gear.

Improper base idle adjustment can cause the vehicle to stall when shifted into drive or reverse

A malfunctioning or damaged carburetor can cause the vehicle to stall when shifted into drive or reverse

Improper ignition timing can cause the vehicle to stall when shifted into drive or reverse.

A malfunctioning or damaged transmission or torque converter can cause the vehicle to stall when shifted into drive or reverse