i have a 86 chevy blazer with a 4 cylinder single throttle body injected motor. the injector is not working i already change the fuel pump and i am getting good fuel pressure but the injector does not want to kick on.

 

an 86 with TBI??? Sure you dont have a carb on that engine with a dead accelerator pump???

 

A 1986 model has TBI. It was the first year.

 

OK cool, when I yanked the engine out of my 85 I could swear it was carb'd...

This is when you want to go invest some cash into some NOID lights (20 bucks you might get some for), and chase the wires for the injector back looking for cracks or pinches. There should be a fuse for the injector that you can check out to. If the wires shorted out it should have popped that fuse on you. Take a look into the harness plug and see if the connectors up inside the plug are still looking good.

 

First thing I would check is if I was getting 12 volts to the injector. Your ECM 1 (10 amp) fuse supplies power straight to the injector via the Red wire. The injector then gets ground through the ECM to pulse. The wire from the injector to the ECM (terminal A5) is Lt Blu. You might try grounding this wire to see if the injector opens.