So here is my dilemma.. I have a 96 blazer (4x4 4.3 vortec). I am having problems getting it started we have changed the fuel filter and tested the fuel pump and its working fine until it gets to the MAP Sensor so it seems, When this first started I got advice from a guy at work to use quickstart, (he thought my gas lines froze up) later for me to find out thats a big no no for the fuel injection system. Anyhow, it does turn over it tries to start but it just wont do it. When we pour gas into the throttle bottle it starts it used to stay running but now it will stall out and runs rough. Is it possible that it is just the MAP Sensor or may I have done some serious damage to the injection system by using that ether?

would appreciate some help here..... thank you

 

What is the fuel pressure reading in PSI? Does the pressure drop once the pump shuts off and if so, how many PSI does it drop? Please be specific.

What do you mean when you say "tested the fuel pump and its working fine until it gets to the MAP sensor"? Fuel does not go to the MAP sensor... How did you test the MAP sensor to determine that it was at fault?

I do not think you hurt anything by using starting fluid. If it starts and runs when you pour gas down the throttle body, that would point straight to a fuel supply problem.

 

I dont know thats how it was explained to me...i was just writing what i was told, they wouldnt let me under to see what was goin on... I was confused when they started talking to me to. Turns out it was the fuel pump afterall got the new one just have to get it installed now. There is a valve on the top on the tank, one nipple one small hose leads off of it. the nipple broke when trying to get the tank down. We have taken this part everywhere and no one seems to have this stupid valve anywhere its a vent or a relief valve of some sort.