my 1995 blazer will not start will crank all day till the battery dies but will not start somebody please help me asap its sitting in a parking lot right now

 

Do you have proper fuel pressure (>55psi) at the fuel pressure test port on the back of the intake between the distributor and the brake booster?

 

Engine needs three things to run; air, fuel, spark.
Air is most likely not a problem. Need to check that fuel is getting to the engine at the proper pressure and that there is spark.

check spark at end of coil wire. Quick check for fuel pressure is to press the scrader valve at back of intake and listen for fuel pump to run.

Good luck.

 

Look at Swart's sig. There is a link to the fuel pressure test procedure. Just because the pump is working doesn't mean it is working properly. You might have fuel but if it isn't the right pressure the truck won't start.

And don't just rule out the air. If the IAC valve is stuck/malfunctioning the truck is not getting the air it needs to start. I find it helps to give an annual maintenance of taking the iac off and cleaning off the pintle post and the opening. It can get residue buildup that can cause the pintle to stick. Simple wd40 and a paper towel will help. But more than likely he needs to go through the pressure test procedure.