Need help, no fuel peasure in my 1997 chevy truck.

5.7 vorteck moter.Fuel pumps cycles on then shuts of after 3 seconds. This what I have done. New preasure regulater, new fuel filter and new fuel pump. Checked ground connection and power going into sending unit all ok. Checked 2 power power going into fuel relay and ground all okay.
Ran jumper in fuel relay contects pump runs continuous as expected then turned truck over while jumper continualy ran pump and truck runs. So being the last and the most simple thing I checked last is it the relay gone bad? Or can it be something else.
The relay didn’t occur to me until late this afternoon and couldn’t make it to the auto store in time.

At witts end and getting close to blowing the truck up.
Any help be much appreciated.

1hl&sinker wrote:

At witts end and getting close to blowing the truck up.
Any help be much appreciated.

wish i could help, but this is all i got: @mdmoen will give you $2k for it if you help him build a ramp to launch it over the ‘sippi. i don’t know if the same offer stands for the Croix

Is there a similar relay (like the AC relay) in the fuse box you could swap it with to see if the problem goes away or travels?

the three second cycle is the computer priming the system which is normal.
there is a relay on the passenger side of the firewall that can go bad.
if I remember right,the fuel pump on that year of truck is wired through the oil pressure switch,if that switch is bad it wont start and run which would explain why it will run when you hot wire the pump.

the oil pressure switch is below the distributor and should have three or four wires on it.
good luck!

Thank you Sheldon, that makes perfect sense. This has been an intermitant problem since last fall. Positive side is there is a whole in the truck bed if the new fuel pump goes bad. and a new fuel preasure reg I wont have to worry about and a shiny new fuel filter that looks out of place amongst the rust under there.

Munchy thanks good sugestion but the rest of the relay are 4 pin.

@pool2fool: I’d have no problem trying to jump it over the river but it’s gotta run….if it runs I assume 1hl&sinker won’t want to jump it over the river.

Quite a quandary. Of course, we could get it rolling down the hill through Hudson and see what happens……

Well the truck is running smoothly with Sheldons help, thank you again Sheldon. A 10 minute job to switch out a sensor. Would have been five but it took me 5 minutes to find the whole.

Now thats its running, maybe if the ball joints and pitman arm and the rest of the steering componants give me grief.

you are welcome !! glad it was something simple for ya !!

Matt Moen wrote:

@pool2fool: I’d have no problem trying to jump it over the river but it’s gotta run….if it runs I assume 1hl&sinker won’t want to jump it over the river.

Quite a quandary. Of course, we could get it rolling down the hill through Hudson and see what happens……

Id get it 3/4 throttle and just send it!!! It’s gonna be a good day!

That’s one bad ass mullet!

this is much more fun !

https://youtu.be/LjYdHzzKTJg!

Eelpoutguy wrote:

That’s one bad ass mullet!

I heard tales of high school kids growing mullets like Larry the Enticer for senior prom this year. There’s hope for America’s youth yet!

Also Sheldon is a godsend to us all!!! No doubt he’s saved several of us unmechanicaly inclined IDOers thousands of dollars. He’s very passionate about helping us. Three cheers for Sheldon! Hip hip horay, hip hip horay, hip hip horay!

Aw shucks,thanks for kind words,just paying back all of the old boys who helped me along the way many many years ago.
that and its fun teaching you guys that things most times are not as scary as it seems and that you can dive in and fix it yourself.

proud of all of you guys for wanting to learn.