Fuel pump is not priming

[choleaoum]

Hey I have a few problems with my S14, I just checked it out. The red and white wire is not getting any power to the fuel pump. So I wired a switched 12v to the fuel pump wire to get the car to start. I changed the fuel pump, changed the fuel filter, and etc. Still no go, I also bypassed the fuel pump relay, still no go either!! What is the problem? Could it be the ECU?

[junn]

make sure the fuel pump relay is getting ground...had the same prob before...if i remember correctly the relay has two 12v and two ground

[choleaoum]

make sure the fuel pump relay is getting ground...had the same prob before...if i remember correctly the relay has two 12v and two ground

The service manual says the fuel pump relay is black, but a DIY says the fuel pump relay is blue.. lol. Which is it? Also, where is the ground of the relays located?

[choleaoum]

Which grounds should I check! =[ The FSM doesn't really state anything.

[Slidin' Sam]

I'm kinda having the same issue right now. I actually pulled the fuel pump out of the tank and jumped power and ground to it and it kicks on. So I know the pump is good. Have power getting to it and all grounds/fuses/relays appear to be good, but I am not getting fuel pressure to the fuel filter. ECU has no codes. I talked with a Japanese friend who has a lot of experience with these cars, and he said that the Cam Angle Sensor could be bad. He said it has happened to him twice before, and when the CAS goes bad, there is something in the wiring that prevents the fuel pump from kicking on. Has anybody else experienced this or hear of this? (the CAS part).

[VNG704]

When my fuel pump wouldn't turn on even though all relays were good, I had a short right after the ignition switch. So basically even though everything (ecu, relays, etc...) was okay the ecu didn't know the car was on when I turned the car on because there was a short. I found out with a digitial multimeter and a wire diagram of the ignition system. Hope that makes since to you.

[Slidin' Sam]

That makes sense, but was the engine cranking or no?

[VNG704]

the engine would not turn, no. I bypassed the clutch relay and it cranked, but didn't run.

[Slidin' Sam]

oh, mine turns...and we dont have a clutch relay on our cars here. :) lol

[choleaoum]

oh, mine turns...and we dont have a clutch relay on our cars here. :) lol

Haha niicce. Well, what I did was send a 12v to the fuel pump and it clicked on and the car runs now. The problem now is how do I make it so I don't have to hardwire it? I have a switched 12v but I don't think it's that great of a "swithced" i'm using the remote wire from the radio. Which means the fuel pump would keep running if the car is left in the on position right?

[Slidin' Sam]

Haha niicce. Well, what I did was send a 12v to the fuel pump and it clicked on and the car runs now. The problem now is how do I make it so I don't have to hardwire it? I have a switched 12v but I don't think it's that great of a "swithced" i'm using the remote wire from the radio. Which means the fuel pump would keep running if the car is left in the on position right?

Your best bet is run power and ground to a switch and then to your fuel pump w/ an inline fuse/relay. They you just have to remember to turn it off when you shut off your car! lol

Did you check for voltage going into the fuel pump before you hard wired it?

Mine has 12 volts flowing into the fuel pump...

[Andres_G]

Hey I have a few problems with my S14, I just checked it out. The red and white wire is not getting any power to the fuel pump.

the plug with that red/white wire is for the gauge cluster. If your checking if 12v is getting to the fuel pump, you have to check the 2 wire plug. 12v will only be there for a few seconds after you turn on the ign.

The service manual says the fuel pump relay is black, but a DIY says the fuel pump relay is blue.. lol. Which is it? Also, where is the ground of the relays located?

The relay is blue. Ground is coming from the ECU into pin #2 of the relay. (will only be there for a few seconds after you turn ign to on)

Which grounds should I check! =[ The FSM doesn't really state anything.
It doesn't...you have to look at diagrams and figure it out. But it does have a trouble shooting flow chart...


Is your fuel pump relay clicking when you turn to IGN to ON?

I'm actually having the same problem. I've narrowed it down to my fuel pump relay. it's not getting ground from the ECU. Also, after I bypass the relay in order to get the pump to turn on, the car will still not start. I'll be taking my car in to a nissan specific shop so they can figure this out since i'm not good at engine troubleshooting.

Let's keep this thread going so we can compare notes on what the problem is :D

[copdodger]

going through the same problems now, for some reason the ecu isn't grounding from the relay. i can jump it, like post #1 here, Fuel pump relay help - 240Atlanta.com (http://240atlanta.com/forums/showthread.php?t=56451), which will cause the pump to run, but i assume its not good to do this.... just cause it doesn't seem right, lol. maybe rather than a solid jumper, wire a switch inline to the inside?? like a fuel pump cutoff



also, heres a good thread about diagnosing fuel pump problems also
http://zilvia.net/f/tech-talk/108545-how-diagnose-malfunctioning-fuel-pump-system.html

[Andres_G]

Will your car start after you bypass the relay?

[choleaoum]

Hmm.. I haven't had a chance to clean the ground but I've heard some people say the wire gets f ried from under the ignition? Anyone have a picture or a good description of it? I can't for the life of me find it, it's a mess under there.

[Andres_G]

The shop found the problem with my car. Frayed wires on the passanger side from when this "body shop" pulled out a dent.

Like my parents say "Lo barato, sale caro". (Cheap stuff, comes out expensive)

[choleaoum]

The shop found the problem with my car. Frayed wires on the passanger side from when this "body shop" pulled out a dent.

Like my parents say "Lo barato, sale caro". (Cheap stuff, comes out expensive)

Was it under the fender? I have frayed wires from the driverside fender. I'll clean them up when I get a chance!