I have a 1987 Ranger 2.9L fuel injected. Got this nice little pickup a few months ago. Changed the air filter, spark plugs and oil and filter. Just recently, it starts and idles, but when you put it in gear, it stalls. The only way I found to get it started is to put the gas pedal to the floor and turn the key to get it to start again. Happend again this morning, got it going and the boy made it to school. Would it have anything to do with the colder mornings? we are in the high 30's, but we start it and idle it for about 5 mintues before he takes off.

What should I be looking at?

 

Welcome to the forum

All fuel injected engines use an air inlet valve to set idle, idle screws wouldn't work, like carbs had
Ford calls their valve an IAC(idle air control) Valve
It will be on the upper intake next to throttle plate, looks like a "can" on its side, and has a 2 wire plug in

All fuel injected engines have a coolant temp "sensor", this is different that the coolant temp Sender that's been used since the 1940's in cars for the dash board temp gauges
Ford calls theirs the ECT(engine coolant temp) sensor, has 2 wires, Sender only has 1 wire in 1987, but they look similar

When engine is cold and you start it, the computer sees the ECT sensor temp is Cold. and sets Choke Mode, high idle plus Rich fuel mix
It uses the IAC Valve to set the higher idle...............does that happen, idle should be above 1,100rpm if outside temp is under 40degF
Then as engine warms up idle will start to go down, its automatic do need to touch the throttle
1,100+ cold, own to 750-800rpms after 4 or 5 mins

Does that happen?
If not replace ECT sensor, it could be reporting higher temp then actual so RPMs are too low for outside temp

After engine is warmed up and idling
Unplug the 2 wire connector on IAC Valve, idle should drop down to 500rpm or engine may stall, either is good, it means IAC Valve was working
If idle doesn't change, and is also not HIGH on cold start, then IAC Valve could be stuck or broken
You can clean it, easy to do and then retest

You should be able to start an ice cold engine and drive it within 30 seconds with no issues, its good to warm it up, but certainly not rquired

Stalling when putting an Automatic in gear means idle was too low, under 750rpm in the case of a V6
The computer does have a Park/Neutral switch on transmission, when shifter is moved out of Park or Neutral the computer should bump up idle by 50-75rpm using IAC Valve
Same would happen if you have AC and it turned on

It reads like IAC valve is not responding or not responding fast enough to prevent stalling

On a 1987 2.9l with distributor there is also the possibility of incorrect spark timing, this can cause stalling at idle when engine gets a Load, in gear, spark is too late so no power and engine stalls
Get a timing light and check it
Should be 19-22deg BTDC on warmed up engine
You need to disconnect SPOUT to set base timing which would then be 10-12deg BTDC

 

Thank you for the thorough reply. I will check these items this weekend and let you know what I find.