fuel pressure will not rise

[jason walker]

I noticed my car would not start last week till it turned over for about 20 seconds acted like it was out of gas but after it started it was fine ran ok . but if I let it set for 30 minutes or more it would do the same thing hard to start but if I turned it off and then restarted it was fine in other words it would crank right back had set my fuel pressure to 42psi originally checked my fuel pressure and it was @ 25 psi so I thought try to turn it up so loosened locking nut on fuel pressure regulator and screwed in adjustment screw pressure would not rise at all . what could be my problem I installed new fuel pump last year it is a DEATSCHWERKS 301-S ... Any ideas ? tried one more time turned on switch heard now fuel pump looked at fuel pressure gauge it was @ 20 or 22 psi

 

[jason walker]

just tried it again same thing so I bypassed the hotwire it plugged all factory wiring back together fuel pressure jumped back to where it is supposed to be any ideas why hot wire kit is not putting all power to pump

 

[Chuck Leeper]

Shorted?
Bad connector?
Dirty connector?

 

[jason walker]

Shorted?
Bad connector?
Dirty connector?

thanks will check all of those

 

[earlbrown]

Sounds like you were having to wait till the oil pressure switch fired the pump up. If you killed it and still has residual pressure in the fuel rail, it would fire right back up.


If you put it back stock and let it sit, will the fuel rail pressurize when you turn the key on? If it does your fuel pressure relay is good and there's something screwy with your wiring.


since you're only making 20PSI you might have an in-tank leak or just low voltage.



Hook your hotwire back up and get a volt meter. does the test indicator show power for 2 seconds after turning the key on?

-if so- does the other small wire on the relay show a ground?

Does the big wire at the relay have power going into the relay?

-if so- does the other big wire show power during the 2 second priming signal during key-on?

 

[dynoman]

Jason, if your car would run with the hot wire system hooked up but would only give you 22 psi and you get full pressure without, it sounds like the pump voltage is low on the hot wire feed. Check the connection at the alternator make sure it's tight, unplug the inline fuse (if it has one) & check connection make sure it fits snug. Lastly change the hot wire relay, that is the only moving part of the hot wire kit and the contacts inside the relay due arc upon opening & closing under load so the contacts get burned after a while . Also it is possible to get what appears to be full voltage at the connectors if the system is not under load (motor disconnected). My bet is the relay is bad.......I change them every other day at work !! Good Luck Sam

 

[jason walker]

thanks for advice will take a day or 2 to check due to my work schedule