1992 toyota 4 runner has hard time starting. I keeping cranking it till it starts which takes about at least a minute to two minutes. when the engine is warm, it starts back up with ease. only when the engine is cold this happens. I have changed almost every fuel part associated with the fuel system except the fuel dampner. any advice?

Have you checked fuel pressure before and after the first attempt to start ?
It could be low fuel pressure or a problem with the cold start injector if equipped.

As with any no start issue, you will need to check for spark and fuel pressure when it won't start to know how to proceed.

try to change the coolant temp sensor.

Is there spark and fuel flow to the engine?

First of all, never... and i mean NEVER, use starting fluid on a gas engine. You will blow intake gaskets, possibly head gaskets, and even warp the valves, and worse yet, blow your head off. Starting fluid is meant for diesel engines, and nothing else.
The first thing you have to do is listen when you first turn on the key, to hear if the fuel pump is running in the gas tank. If you can't hear it, check fuses and wiring. Make sure there is power to the pump by using a test light. If there is power, and it doesn't work, replace the pump.
Check for spark using a timing light. If there is no spark, check the coil, fuses, distributor, wiring, etc. Aim your timing light at the crank mark, if you have spark, and make sure the mark is staying in one place. If it is jumping around, your timing chain has likely jumped, and will need to be replaced.
If there is an engine light on, you are best off to borrow a scanner if you don't have one, and see what it says. Hit and miss can end up costing much more than the price of a scanner. Good luck.

does it have three second fuel pump run when you turn key to run position/ in between you should let i rest 5 or so seconds then try it again also some of these cadilacs have oil pressure sending unit wich takes the duty of keeping fuel pressure up is fuel pressure lowering as engine quits eg. rev up some in your few seconds of running while the engine is quit momentum keeps it turning for a short time see if you r pressure maintain thru the wind down

Buy a high amperage cold cranking battery! Typically there used in diesel engines, this will solve any hard starts!

most likely its ur battery is almost dead

if its over the fill line yes it is a problem. did you wait 5 minutes after runing the engine then check? if you did and the oil is high i would think this is a problem. you can get a trukey baster or hand pump and pump some oil out the fill cap.

bad fan relay.see if your radeater has good flow. if you keep running it like that you will lose your motor