i have a 95 cheavy 3500 5.7

Would any one now the problem y it could not be holding idle??

There are several things that could cause this. Dirty fuel injectors could hamper idle, run some good fuel injector cleaner threw the gas. Change out the fuel filter also. Another possibility could be a vacuum leak, common spot is the TBI base gasket should be checked by removing the TBI. Once the TBI is removed you should remove the AIC / Air Idle Control sensor from the TBI and clean out the port for the AIC & Throttle Body good with carburetor cleaner. The AIC sensor should be checked, I believe Auto Zone can check it, may have to be replaced. Also check any other vacuum sources & lines for vacuum lines for cracks & leaks.

Ok rowefast cause ive changed map sensor,egr regulator,the throttle regulator, air idle control,2 tempreture sensors on the block and even new spark plugs and wires..........now I gotta like warm the truck up till it heats up then it will idle for like ten minutes then it will die out so u really think I should take off the tbi?? and clean it and if so do I need to buy a gasket to put it back on?????

Not asking you to buy anything. Just want you to do diagnosis. Could be vacuum, could be a fuel issue, or it could be in the ECM. All can be tested without replacing anything.

Ok Thankz I jus rebuilt the carborator so ill let u now how it go's.....

Hey rowefast my truck idles but wen gets put into gear it dies out would u now the cause of that??

If you are having the same symptoms, a cause could be in the Ignition Control Module in the distributor. Once they start to break down heat is a major factor to this component. The ICM takes the place of the old point system. I do believe Auto Zone can test this, some stores can some stores can't. If you remove this for any reason make sure you put dielectric grease back under the unit.