Hi, How do i tell if i have a dead fuel pump or relay? No pump noise at key on... ( verified by fuel press guage ) Car was idling in garage .. i was collecting a data log to try out a new bin i'm working on, Pump is original 1992 vintage and has aprox 60 on the clock. The data i collected during the no start condition shows NO voltage at the fuel pump ( via TP/RT ) but yet voltage appears during cranking then goes to zero when cranking stops
I even tried the prime wire near the relays ( advice from GM mechanic friend )
supposed to go direct to pump but with 12 volts applied still silence, any thoughts? I really want to make sure it is the pump and not something else, thanks GTA....

 

Which wire did you apply voltage to?(color,size)

I just had to replace the fuel pump on my fathers '94 chevy pickup with 54k on the odo. Age is everything.

 

I applied 12 v to the red wire ( flat spade connector ) this wire is sticking out of the wireing harness near the relays on the driverside firewall. I was told to do this by my mechanic to verifiy a dead pump....

 

That's interesting. Never heard of a wire with a spade connector on it sticking out of your harness to be a good thing.

However your fuel pump relay should have a gray wire coming out of it, this is the one you want to apply 12volts to.

 

sorry i should be more specific... the wire yes its red, that was the color he told me to look for the connector is a female end that requires the flat spade connector. Which relay controls the pump, left or right? maybe i can swap them around to verifiy correct operation?

 

I'm not sure whether its the left or right because I have an '89....But it should be the only relay there with a solid gray wire, this runs through the fuel pump fuse and supplys power to the pump. Wouldn't be a bad idea to check that fuse as well in case you haven't.

 

89 thanks for the reply...

I checked the fuse box and i do not see any fuse that is dedicated or together with something else for the fuel pump, i am going back to check in the am again would a blown relay show the symptoms that i am describing?
Everthing shows normal except no fuel pump, BTW how the heck do i post a TP xdl file on here to show you what i mean? thanks GTA.....

 

I have no idea about posting tuning files. But I know how to hotwire a fuel pump .

Oh, assuming its like any other document file try saving it as a .jpeg and posting as a picture.

 

hmm, just noticed something when reviewing my data log of the no start condition....Key on there is NO voltage at the pump ( via TP/RT ) during cranking the voltage goes up to normal BUT the Inj PW remains at zero?? when cranking stops pump voltage falls to zero....what the heck is going on?