fuel?

[creepy guy]

I have a '87 runner with a fuel delivery problem, it has a brand new fuel pump and filter but will not pressurize the system. The fuel pump will run if the key is tuned all the way to 'start' but as soon as it is released to the 'on' position the pump shuts off. Anybody got any ideas?

 

[turboSR5]

Could be your AFM. The fuel pump circuit relies on a signal from the AFM that indicates that the vane has opened and the engine is running. This is a safety feature in case you roll over or something and the engine dies, you wouldn't want your pump to keep running and pooling gasoline all around you.

 

[creepy guy]

thanks man, I'll check it out

 

[fourwd1]

To troubleshoot you can bypass that circuit by putting a jumper between the +B and Fp terminals on the test connector mounted adjacent to the engine bay fuse box.

 

[fourwd1]

That will bypass the interlocks on the fuel pump power.

 

[creepy guy]

got any other ideas? the bypass didn't work

 

[papawhellie]

Having same issues. Guy swapped my motor in today and pump won't pump. I am unsure if the fuel pump relay is in it. I removed it to try and crank my wrecked one the motor came from. Jumping the f to the b in the box also bypasses that? Straight 12v to the pump she cranks and runs. Spit a few and run a second otherwise. AFM is flapping. Ideas?