When I start the truck when cold the idle goes up to high mayby 2500 rpm. After it warm and touch the gas it runs normal but when put in gear it idles low and runs rough. It run pretty good for an 87 with 207k miles, but when you come to a stop it idles so low it fells like it wants to cut off.

This is normally the way it is suppose to work. You need to have the RPM measured for High RPM and duration. What you are describing is how an electronic choke is suppose to work.

The errors would be how high the RPM goes and for how long it lasts. When cold the RPM, fuel mix and timing are changed to give a rich fuel mix. As the O2 sensors warm(Could be defective) they signal the engine to lean up. The water thermostat also has something to do changing the engine to a lean running slow condition.

If obtaining heat from your heater seems to take Forever, the thermostat could be weak. This would coincide with the engine continuing at a high RPM longer because it is not warming up.

The throttle position sensor may be causing your issue----This sensor monitors the outside air temp.In the winter the throttle opens up far because th.e air temp is cold and vice versus

Without checking your car physically, its not possible to give you any idea what it could be or not

Check out related help links to troubleshoot these problem:----Click the link below:---Idles Fine but RPM jumps in drive mode?http://technoanswers.blogspot.in/2012/07/idles-fine-but-rpm-jumps-in-drive-mode.html
---------Mitsubishi Lancer rpm needle bounces?http://technoanswers.blogspot.in/2012/02/mitsubishi-lancer-rpm-needle-bounces.html
--------How to adjust rpm on 2009 dodge charger SRT8?

http://schematicsdiagram.blogspot.com/2011/12/how-to-adjust-rpm-on-2009-dodge-charger.html
---------
Engine cuts out at 3000 RPM?http://schematicsdiagram.blogspot.com/2011/12/engine-cuts-out-at-3000-rpm.html

---------

Cold start problem and vehicle shudder around 2500 to 3500 rpms
http://repairhelpcenter.blogspot.com/2012/10/cold-start-problem-and-vehicle-shudder.html

---------
High rpm in neutral? Inconsistant high RPM in neutral?http://technoanswers.blogspot.in/2012/02/high-rpm-in-neutral-inconsistant-high.html

-----------
Jetski Sputters and Low RPM? http://whatisbyme.blogspot.in/2012/07/jetski-sputters-and-low-rpm.html

--------
Fuel Injection Problem And RPM suddenly increaseshttp://whatisbyme.blogspot.in/2012/07/fuel-injection-problem-and-rpm-suddenly.html

----------
2005 Toyota Highlander: Engine runs hard RPM below 3000?http://whatisbyme.blogspot.in/2012/05/2005-toyota-highlander-engine-runs-hard.html

---------
1987 Toyota Camry: RPM Drops going Up hills?http://whatisbyme.blogspot.in/2012/05/1987-toyota-camry-rpm-drops-going-up.html

-----------
Cruise Control stops working, Excessive cranks to start the engine and RPM goes max 2500 http://whoisbyme.blogspot.in/2012/07/cruise-control-stops-workingexcessive.html

----------
1990 Toyota 4Runner: Engine cuts off when reaches 2000 RPM?

http://whatisbyme.blogspot.in/2012/05/1990-toyota-4runner-engine-cuts-off.html

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

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

---------
1995 Toyota LS: Misfire at idle or low RPMhttp://whatisbyme.blogspot.in/2012/04/1995-toyota-ls-misfire-at-idle-or-low.html

-----------
Lexus RX: Tapping noise under Valve Cover At Low RPM?http://technoanswers.blogspot.in/2012/04/lexus-rx-tapping-noise-under-valve.html

----------
These will help.
Thanks.

Sounds like a coolant sensor problem. It signals the ECU for open loop, cold start rich, high idle, until warm up is reached.

Check the water coolant thermostat. If it is stuck in the "open" position you are heating up all the water in the coolant system and this will take time. The thermostat keeps the water in the engine until warmed up to almost normal running temperature, only then does it allow the coolant to enter the radiator.

It sounds like your idle control valve is sticking. The video shows you where they are located on a 97 Buick but it is the same engine.
This video shows you how to replace them.

Buy a bottle of Techron Fuel injector cleaner. It's sold in many grocery stores and all auto parts stores. Pour the whole bottle into the gas tank when you can fill up. Drive the car and don't put more gas in until the car is almost empty. That should fix it

Idle flare is normal on all newer fuel injected cars. I think maybe you got a little paranoid,probably first spark plug change done by you. Gas milelage is easily explained in 2 ways, one the gov't is making the gas companies put oxygenated fuel into the gas & 2 you could go with a set of bosch oxygen sensors,pick up 15% more gas mileage

Sounds like you have a vacuum leak in the air intake side. Check all your small and large hoses around the throttle body. Also check your idle air valve....cylindrical device connected to the the air box at the front of the engine.