need help!

[blake930]

hey I am new to this site and need help finding out what is wrong with my truck. As soon as you start it up it idles perfectly fine and takes off good then it starts to have no power like it's starving for fuel . But if you turn it off and back on it takes off fine but go's back to no power. I have replaced all spark plugs and wires, distributor cap, rotor button, fuel filter,manifold absolute pressure sensor and coolant temperature sensor. Thank you.

 

[nvrenuf]

Need truck info.

 

[blake930]

1987 Chevy k5 blazer 350 5.7L

 

[ktmoutfront]

Drive it again with the air cleaner off. When it looses power, look at the injector flow. Is it dripping or a fan spray?

 

[blake930]

Both have a slight drip

 

[ktmoutfront]

While running?

Do you have a fuel presure gauge you can add?

 

[blake930]

Yes while running and no I do not

 

[ktmoutfront]

My guess is fuel presure dropping off. Bad pump. I've also seen a piece of hose deteriorate and a flap inside the hose do that.

 

[blake930]

Thanks for the help gonna try the pump

 

[ktmoutfront]

Before you pull the tank, remove the presure line at the throttle body. Run a temp hose from it to a gas can so you can watch the flow. Find the pig tail wire on the fuel pump relay. Run a line from + side of the battery to the pig tail. Watch the flow.

Needless to say, watch the arcing when doing this.

 

[blake930]

Alright will do thanks again I'll keep you updated