ill try to be at thorough as i can with my issue.

i have a 1993 with only 53,000 miles on it.

since the car has been in my possession over these last few months, my problem gets worse and worse.

when i turn the key to "on" (right before i am going to crank the motor over) the instrument panel looks like this:



notice that the "check fuel" light is not lit. when you go to crank it, it just sits there and cranks and cranks but will not start. also you can NOT hear the fuel pump kick on at this time.


now sometimes when im getting lucky, when i turn the key to "on" (again, right before i am going to crank the motor over), the light comes:



when this happens i CAN hear the fuel pump kick on, then when you go to crank it over of course it fires right up.

before if the light didnt come on, i would flip the key back and forth really fast and eventually it turned on, you could hear the pump kick in and it would fire up but as of lately this great method does not work... also i would like to note even when driving the car will just die for no reason and when you go to flip the key back to "on" the light wont come in, so then ill have to pull over and wait and mess around...

so what might the deal be? im stumped personally... tried leaving the battery disconnected for quite a long time to reset the ECU, hoping that might do something but of course no, that would be to easy, heh

my next plan of attack was to do a manual switch straight from the battery to the fuel pump to see if it will kick on that way, but i do NOT know what wires are + and - on the fuel pump itself...

i have the whole back seat torn out so its VERY easy to hear the pump go on and off plus get to the wiring.

any and all feedback is more appreciative and i apoligize for the long post!

-Roo

 

Well..first that is not the "check fuel" light. That is the check engine light,It is hook up to your cars engine control computer or ECU for short...Sounds like you got a loose connection somewhere. Check your wiring. Oh and welcome to the org.

 

i forgot to mention the car is 100% stock and has never had ANYTHING messed with. (it was my grandmas car before it was passed on to me)

ive checked wires, fuses, etc. and nothing... when YOU say wirings which are you referring to?

-Roo

 

The problem you are describing is a intermittent problem. sometimes problems like that are due to loose connections in your wiring. check out the General Maintenance Reference Links.

 

bump bump bump

 

I would suspect a fuel pump relay or the fuel pump itself.. but usally the pump either works or doesn't. check the fuel pump relay and see if it's working properly. the relay is in the trunk, just to the right of the driver's side tail light (behind the carpet, near the turnk latch).
one relay is for the trunk latch itself, the other is for the fuel pump.

 

?
Sorry im a little out of the loop.

 

Is it the same as the other relays?? ie.. he can swap it with one of the same color and test? If not, he can get one from a boneyard cheap and test

 

I don't think it's the same, but not positive. You'd just have to pull some and try and match up the terminal patterns, I guess. I just bought a new one from Autozone for like $12, so even if he had to do that, it wouldn't break him.

I agree with Matt that it's probably not the pump itself. It's more likely in the circuit before you get to the pump. Maybe even in your ignition switch, like maybe something internal isn't making contact all the time. Since it sometimes works and sometimes doesn't, it wouldn't be a fuse, but I guess I'd check everything anyway. Sometimes it's the simplest thing that causes the problem.

 

it won't be in the ignition switch. if the rest of the lights come on on the dash, then the ignition switch is fine. the fuel pump signal is an output on the ECU.. it runs back to a relay in the trunk, which then runs to the fuel pump.. it will most likely be something in that line. main point of failure is the relay. after that it's the fuel pump..

also check fuses though to make sure they're getting good connection. sometimes they will corrode and cause problems like this.

 

ok, heres the scoop.... found the two relays in the trunk. ones green and ones orange. the ORANGE one is the fuel pump relay...

the other one (GREEN) IS NOT the trunk latch relay (i unplugged it and hit the hatch release, still worked)...

ok so this is weird...

first i just put the key to on, light was not on, car wouldnt start...

i UNPLUGGED the fuel relay, go back to turn the key to on, and sure enough, the yellow light on the dash comes on. crank it for ****s and giggles and of course does not start since relay is not plugged in. so i go back to plug in the relay, yellow light still on and it fires right up.

turned car on and off a few times then finally the yellow light wouldnt come back on... tried the unplugging and plugging in of the relay to see if i could get to do the samething but of course it didnt and back to no yellow light (no running car).

so at this point im going to bite the bullet, blame it on the fuel relay and go pick up a new one tomorrow and hope for the best!

if that doesnt work, gonna say screw it and hardwire the fuel pump... only i dont know what wires are + and - for the pump... how would i go about figuring this out?

i know my cars, but a total dumbass when it comes to electrical...

thanks all who replied, i greatly appreciate your input!

bump = desperate fools like me attempt to get thread moved to top of list on forum heh

-Roo

 

it requires you to pull the fuel pump out of the tank, but the wires will be red and black on the pump- or at least labelled on that side.

they're also listed in the nissan FSM if you have one- I'm guessing you don't.


but from what you've said, it sounds to me like the fuel pump and relay are working properly.
what you can do--and my suggestion--is to run a wire from your ignition switch that runs when you're on "on" or "start" (there's a wire on the steering column for this to run the ECU and fuel pump while engine is cranking). run that wire to the fuel pump relay and bypass the ECU. If you still have probelms, then it will be the pump or the relay itself. but if you're replacing the relay, then that part is taken out of the question...

BUT... here's the good news.....
since the check engine light is on, the ECU will have a fault code stored in it.. get into the ECU diagnostic mode by removing the pass side center console cover and turning the screw on the ECU clockwise for a few seconds, then turn it back. turn the ignition to "on" but don't start the car. at that point, the check engine light should flash a series of short and long flashes. that will give you the error code.. look in the stickies for the explanations on that... but that may also help you figure this out.

hope that all makes sense.. I just had a pitcher of margaritas with dinner.

 

Well, the other good news is that even with a pitcher of margaritas under his belt, Matt still probably knows what he's talking about. ;0

One correction, though- the green one IS the pump relay. The orange one is listed in the manual as the "safety" relay. The trunk lid relay is actually on the opposite side of the latch from these 2, and it's blue. I did the exact same thing you did, though, before I looked at the manual.

 

then how come when the car was running and i yanked the ORANGE relay, the car died?

and what the purpose of this "safety" relay?

-Roo

 

someone already mentioned it, that's not your "fuel pump" light. it's your engine check light. however, if you're thinking you're having a bad relay like someone mentioned here then go to the junkyard and get yourself a handful of relays/fuses/etc... and start trying out one by one. it shouldn't cost you no more than $5 while a brand new relay will go for $20/pc

 

Can't tell you the purpose, cause I don't know. It's apparently important enough to keep the car from running if it's bad, though. (or not installed). The info I got was directly out of the Haynes manual, so it should be correct.

 

it's probably a failsafe to shut off the car's fuel pump in case of something happening

 

check the ground wires by the injectors if there green or covered in rust that happens or if they broke or were cut it happen s no ground in put form the injectors will throw the ecu in to protection mode

 

the safety relay is only on the VG model according the to FSM. I am pretty sure I've read that its supposed to protect the car if the battery cables were reversed (or you jumped it backwards), but I can't find where I read that so maybe I'm way off

and yes, the fuel pump relay is the green one

 

Safety relay could be attached to an inertia switch?? ie.. if you get rearended hard enough, the pump doesn't stay on and pump fuel all over everything and result in a firery ball of maxima fury

 

if the check engine light isn't coming on, that means that the ecu isn't getting power.. the ecu controls the fuel pump relay to turn the pump on for a few seconds before it cranks to increase the presure in the fuel line so that it will start easier. if the ecu doesn't get power, then the fuel pump won't turn on, so even if you hotwired the fuel pump, your car still won't start because the injectors and ignition wouldn't work. the reason the car would shut off is because of the same thing, when the ecu looses power, it's just like turning the key off while driving.

you need to get your hands on a wiring diagram, and follow the power wires and the ground wires. here's another thing to try... take a voltage meter, and check all the wires that provide power to the ecu. when the light doesn't come on, check the same wires that does give power when the light is on. if ever power wire checks out, then find the ground wires and check them. if you loose connection with a ground when the light is off, and you have conitunity when the light is on, then it's a ground... if your power and ground checks out, then it's your ecu.

 

Take the car to a Nissan Dealership and have them diagnose it. If you don't understand what exactly is wrong with your car or how to find out what the "Check Engine" Light looks like then dont mess around with your fuel pump or it's relays.

For all you may know your alternator may be kickin the bucket. Have that checked first since it is your check engine light on. The check fuel light is right next to the fuel guage.

 

Here's how most Nissan dealers approach problems.
Keep replacing parts (at full retail for labor/parts) until the problem goes away. Not really what this guy is particualarly looking for.

Methos has the best suggestion IMHO