Fuel pressure shoots up to 60 PSI but drops to nearly 40 I was just able to get my tester set up on it

 

Its current 71 here now with the vehicle sitting in direct sun and the barometric pressure is 14.69 psi here also

 

That fuel pressure drop needs to be addressed. Next test fuel pressure at the output of the fuel filter under the vehicle to determine if it’s the fuel pump/tank or the Plenum/Regulator/injectors..

George

 

I am lost now I can’t get this Blazer to start at all it tries to crank but then just locks and nothing but the bendix spinning

 

because the vehicles parked in direct sun, it’s hard to say if you’re too temperature sensors are accurate, but they’re fairly close. That atmospheric pressure reading is pretty far off though, so there may be an issue with the map sensor.

George

 

[QUOTE=matthewsjeremiah1983;753151]I am lost now I can’t get this Blazer to start at all it tries to crank but then just locks and nothing but the bendix spinning[/QUOTE

Remove the battery cables from the battery, wire, brush and sand. All the connections and re-tighten then measure the resting battery voltage with the meter leads on the battery post. Then tell me that same voltage reading when you try to engage the starter..

George

 

The MAP sensor is new but I can’t tell about the fuel pressure when the switch is on it shoots to 60 psi but when the pump kicks off it drops to nearly 40, should I try at the filter to see what I am getting? I don’t smell gas in the intake at all but 🤷‍♂️

 

What brand is the MAP sensor?

Yes you need the fuel pressure ten minute leak down at the fuel filter outlet.

George

 

I am in the midst of the fuel test at the filter, I had to plug in to the inbound side of the filter and I got 60 but as soon as the pump kicks off it’s down to 40 so I believe the pump is bad and I need to change the filter as the fuel that came out of it was dark looking

 

The MAP sensor is Standard ignition also