Why does it idle but stalls when in gear?

not told at all if it fails hot and cold engine
if fails cold , rpm is 1200 to 1500 rpm
if fails hot engine, idle it for 15 to 30mins until hot
and RPM is 800 not 400, if idle is not 800 ISC is dead.
the PCM controls idle, via ISC/IAC or TWB (no usa 2.4 has TWB)
no VIN told no engine told so I post in generic ways./
guess is 2.4 L KA24DE I4
KA24DE , inline 4.
top cause is not the transmission!!!
but gee the scan tool tells why it stalls most the time but you did not scan it first so have no clues why.

it is weak engine power. in fact super weak.
stalls in Drive, and reverse and in low (PRNDL)
the #1 causes is ISC dead, idle controls
as you shift to D/R/L the ISC opens for more power at idle for preventing the stall you have. so why not scan the PCM to see whY?
here are more causes. (not a full list or the 20 tests to learn it)
fuel pressure way low, not dead, nor zero just low! from spec.

so engine power is weak even going into gear, 1st
there are other causes, and lots of tests no blind poster to guess.
1: CAT melted. making engine, 1/5 normal power or less.
2: fuel filter near packed and clogged up. weak pump or
3: bad FPR< causing low fuel pressure at idle.
4: ISC stuck (means the PCM cant raise it to let DRIVE not stall.
5: throttle by wire parts (TBW ) bad, scans tell most of this.
6: fuel filter packed.
7: bad fuel.
8: in some rare cases the TC is locked up, and stalls engine.
one way to learn this is to use the throttle pedal at 5%
put foot on throttle , no kid near by
and nothing to hit ,front or rear of car.
put wheel chocks on tires (4"x4" lumber works)so can not roll.
now foot on brake and hand brake set! 3 ways safe.
add some 5% more throttle to say 1000 to 1200 RPM and shift to drive or reverse, in the safe direction I can not see.
the car may bang in to gear hard, so use right foot gently.


and see if it stalls now. (this test simulates an ISC air valve)
if not stalls the ISC is stuck. 90% of time.
ISC = idle speed controller. or TBW is failng.
we can also test fuel pressure doing all that and if too low BINGO
forget the $3000 transmission swaps.
learn to assume cheap bad parts are bad for $20 not $3000 first.
and win. even have money left for IRA or 401k to invest.

if TC is locked up (rare) test it buy starting car in PARK and then neutral both, see if engine acts up. different.

scan the PCM , check all fuses.
is first,
or tow it to any ASE shop in town and say Diagnose it please.
as 99% do today,.

ok our 2.4L usa car
has a complex 3way IAC
thermal #1, IAC and 2 electric valves, 2 and 3
if fails this part in any of 3ways. shifts to drive will stall
not saying I know it is bad but you never scanned the PCm

IAC 3way

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 .

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

Automatic transmission ??
Check engine lamp illuminated ??
Cold engine idle speed ??
Warm engine idle speed ??
IAC (Idle air control) system operation ??

If you need further help, reach me via phone at https://www.6ya.com/expert/ralph_2f0886b7d6af32ce

low engine power.. which engine, there are 7 .
ever put in a new timing belt , 60,000 mles service it is.
if not it slips and power goes byebye.

if you use your right foot to stop the stall does it, and if you do that
do you get full power>?
if yes, yes, then the ISC is stuck closed or EGR stuck open.

the ECU raises the ISC valve to keep a/t from stalling,
it open the valve at the moment of the shift to any gear.
P/n to any gears. if it cant open it will stall.
that is how the idle controls work.

You'll need to change the distributor, as the distributor shaft oil seal has gone bad. Without sufficient spark, you'll have no power. Don't forget a new cap/rotor.

It can be low fuel pressure issue or clogged fuel pump.Or its engine related issues,---------------
Check the help link mentioned below to troubleshoot the problem :------

Engine stalls when gas is given?

http://technoanswers.blogspot.in/2012/01/engine-stalls-when-gas-is-given.html

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http://technoanswers.blogspot.in/2012/01/car-stalls-when-maf-sensor-is-connected.html

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Car Engine Stalls While Driving?

http://schematicsdiagram.blogspot.com/2011/12/car-engine-stalls-while-driving.html

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Car stalls and throws white smoke from exhaust?

http://repairhelpcenter.blogspot.com/2012/01/car-stalls-and-throws-white-smoke-from.html

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Stalls And Dies At Stop Sign?

http://www.howtobyme.blogspot.com/2012/07/stalls-and-dies-at-stop-sign.html

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GMC Sonoma Stalls and idles low

http://technoanswers.blogspot.com/2012/10/gmc-sonoma-stalls-and-idles-low.html

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Nissan Pathfinder stalls and bucks on Acceleration?

http://technoanswers.blogspot.in/2012/02/nissan-pathfinder-stalls-and-bucks-on.html

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1992 Chevrolet stalls and shutdown?

http://schematicsdiagram.blogspot.in/2012/04/1992-chevrolet-stalls-and-shutdown.html

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Stumbling and stalling at idle after engine rebuild?

http://schematicsdiagram.blogspot.in/2012/03/stumbling-and-stalling-at-idle-after.html

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1990 mazda 323 stalls and quit running?

http://technoanswers.blogspot.in/2012/02/1990-mazda-323-stalls-and-quit-running.html

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2000 Toyota Camry: Idling and Stalling Problem?

http://whatisbyme.blogspot.in/2012/05/2000-toyota-camry-idling-and-stalling.html

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1995 Toyota Corolla: Stalls, Sputters and Pops Through Intake Manifold?

http://whatisbyme.blogspot.in/2012/05/1995-toyota-corolla-stalls-sputters-and.html

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1999 Toyota Camry: Erratic stalling and high engine RPM at idle?

http://whatisbyme.blogspot.in/2012/05/1999-toyota-camry-erratic-stalling-and.html

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Dodge Dakota stalls, stumbles at idle. Has low fuel flow and runs hot?

http://schematicsdiagram.blogspot.in/2012/03/dodge-dakota-stallsstumbles-at-idlehas.html

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1994 Toyota 4Runner: Stalls and Stops While Driving?

http://whatisbyme.blogspot.in/2012/05/1994-toyota-4runner-stalls-and-stops.html

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1997 Toyota Camry: Erratic Idle and Intermittent engine stalling?

http://technoanswers.blogspot.in/2012/04/1997-toyota-camry-erratic-idle-and.html

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Ford Maverick: No Idle and Stalling issues?

http://schematicsdiagram.blogspot.in/2012/04/ford-maverick-no-idle-and-stalling.html

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These details will help.
Thanks.

Usually a sign of a dirty throttle body or a faulty idle air control valve.
If it dies like the transmission is engaged, the torque converter could be locked up.

Wow you change everything, TPS was right thing to do and so is the Idle air control,and MAF and EGR, fuel pressure, So it idles high then some one tried to defeat the stall in gear? Even if there is a vacuum leak creating high idle it shouldnt stall in gear, , What color is the transmission fluid? when in gear in drive step on the acelerator pedal to maintain idle to prevent car from stalling. Just enough to maintain let say 1100RPM. Is there a vibration? I mean a torque convertor vibration. Torque convertor stall are common an GM and Nissan,very rare do I ever see it on Ford. I really belive the IAC is not getting power and is just been adjusted manually, cause I know its not the transmission, At idle in gear pull the plug on the idle Air control does it change in idle setting? If it doesnt change in Idle setting the adjustment that was use to control the setting lower the idle to its normal setting. Plug the idle air control in then.The idle air should change the setting. If it doesnt its not getting the signal it should.

sounds like your catalytic converter is clogged and not letting your exhaust gasses escape.. have a quality muffler shop check it out. you will notice because it will be red hot..