cold start
 

is there a adjustment on the idle when the motor starts up cold? when the motor is up to temp it does idle at bout 800 rpm and thats 50 rpm above what it is suppose to. when it starts up cold it jumps to 1650 rpm. then after it warms up it goes down to 800. i just don't like it jumpin that high first thing in the morning.

Cold start high idle is normal. I think mine is close to 2k rpms when stone cold.

Rob

the cold start idle speed not adjustable. also, the colder it is the higher it will idle. depending on the year, the auxilary air valve may be electrically heated or heated by coolant.
you can turn the screw (about 1/2" diameter) on top of the throttle body to lower the warm idle to 750.

Around 40* F or so my truck idles around 1500 when cold.

on my 88' , I have that big plastic screw, that is spring loaded, on top of the efi box, turned all the way down. so far the idle is 700 rpms. It has not gotten cold here in Houston yet, but it will be starting today, so when I get it out of the shop, I will check that out, to see if the cold start goes to a higher rpm.

Do you have A/C? I'm pretty sure that is for the A/C idle up relay

rangerruck:
with a/c, that 'big plastic screw', the a/c idle up valve, is used to set the idle speed when the a/c compressor is on so that the drag from the compressor doesn't cause the engine idle speed to drop too low, causing ineffective a/c operation at idle. if adjusting that screw with the a/c off mucks with your idle, somethings wrong with your truck, likely the VSV associated with the a/c system is malfunctioning.

Cold Temp, high idle is normal. Its there to speed up the cold lubrication quicker. As long as you have the proper weight oil 10w-30 you are fine. I would wait till it idles down to move..

Normal. I just wait till the idle drops down to about 1,000rpm. Or untill the thermostat opens up, then I go :)