I just changed the fuel pump yesterday, NOW I think its not the pump, could it be the relay? It was working yesterday now its not working.......3.1

 

better check the wiring connections again since you just fiddled with them...

 

OK, here's what I figured out today. When I got home from work I tried to start the car but it wouldnt start, didnt hear fuel pump running either. So I unhook the battery, waited a few mins, hooked it back up, and then when I tried to start it, I HEAR the pump and it starts. So I play with it for a lil while to see if it is going to act up again, and it doesnt...........YET!!!! I am going to try it again in the morning to see if it will start, if not I will be back to square 1..............any ideas???? bad relay, ecm, or something else???

 

i am having sort of the same problem i replaced my pump and relay and when i turn the key on i do not hear the pump run ,but when i start cranking (maybe 30 seconds to a minute, the pump runs and once the car starts it runs fine it just makes it a little hard to start when the car sits a while also i had no problem before i replaced them

 

you have me thinking i might not have disconnected the battery (i know i should have i just cant remember) the computer might have to reset itself , i'm going to try, it il let you know the out come

 

jukna:
the reason your car fires after 30 seconds of cranking is that our cars are equiped with an oil pressure switch. (located near the oil filter IIRC) once oil pressure builds this switch bypasses the Fuel Pump relay and provides power to the fuel pump to allow the engine to start. it is like an emergency backup so a bad fuel pump relay does not leave you stranded. I would re-test your fuel pump relay.

check the Fuel Pump fuse in the fusebox as well.

 

OK, got home today. Tried to start car....... NO LUCK!! Didnt even hear the pump. Tried the battery deal again....NOTHING!! So I rechecked eveything and found NOTHING!! I had to get the testlight back out AGAIN. Traced power all the way back to the harness behind the rear seat........SO....I am thinking....BAD pump? I have seen it happen B4......but never to me so NOW i have to drop the tank AGAIN!!!!!

 

beforte you do that.... try applying 12V to the pump from the battery. bypass all the other wiring and make sure it's the pump before you pull it. also, check your ground. the fuel pump grounds to that screw under your drivers side rear seat (pull the seat and you will see it, make sure the wire is hooked up)

 

I have three wires at the harness Gray/Black w/White stripe/Purple w/Black stripe.............I am guessing that the purple wire goes to the fuel gauge and the other two run to the relay?? I will check to see but I traced it before and and thought all the wires run under th dash... thanks for the info...

 

thanks for the info, i will check it,may also change the harness looks a little old

 

i just went threw all this my self, the purple is the wire for the sending unit, the gray is the power for the pump and you can guess what the black is lol, but yea just use a battery charger and throw power to the gray wire to check the pump.... if it doesn't start i pitty u cuz those tanks are a b**** to drop. good luck

 

1 quick question! Is the purple wire suppose to have any power in it? just thought I would ask, cause I didnt know......


And I have power all the way to the tank in the gray wire......

 

it is a signal wire. it's resistance will varry from 0 ohms to 90 ohms. if your fuel guage works there is no problem with the purple wire. ignore it.


and the pump does not run? check your ground for sure, if it's good then you have a bad pump or wire fault closer to the pump then where you are testing. i would hit a junkyard and snag another pigtail for the pump, then plug that in to the harness (so it's no longer connected to your body wiring and run the black to your battery and the red to your batter (use jumper cables as test leads). does it still not run?

 

I am thinking it is the pump, i ran a hot wire to the gray wire today and.......................NOTHING!! So it is time to drop tank...

 

have you checked the ground yet? take a hot wire and connect it to the clip on your test light, jam the test light into the black wire by the fuel pump. does it light? if not you have problems. do this before dropping the tank.

if the ground is good then I agree you have a bad pump

 

just plug a hot wire into the very 1st plug in spot on the bottom row of the diagnostics port inside the car under the driver side of dash

 

looked for one awhile back..... and I dont have nothing in this spot.

 

if it did not work with the jumper wires it is nbot going to work with the ALDL thing either.

 

I had similar problem after puttign in new pump was the bluck head connector. Thing that runs the wires for the tank through the metal with a plug. Ended up wiring direct though the hole I cut to change pump.

Which means ir probably wasn't my pump either but new is good.
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Also tried to wire it direct with a switch but that would blow the fuse for the pump in the front fender.

 

Just a couple of questions for the original poster. First of all, exactly when are you listening for the fuel pump? With the key on (no start), the pump will prime for a few seconds, but will not come back on until a certain amount of oil pressure is realized....

Now, you said you had the new pump working at one point, right? "OK, here's what I figured out today. When I got home from work I tried to start the car but it wouldnt start, didnt hear fuel pump running either. So I unhook the battery, waited a few mins, hooked it back up, and then when I tried to start it, I HEAR the pump and it starts...."

After that happened, your now saying that the pump is no longer being triggered at all, correct? Here it sounds like you blew your pumps fuse. Double check your fuel pump's fuse in the engine bay, it will be bolted (via the connector) to the frame (by the inner fender)....

I just don't see how a new pump can work at one point, then instantly go bad (for no apparent reason). There's more to the intank pump than you think, as voltage is regulated by, and through the ECM. Could be somewhere in your ESC as well, as here you'll find your main FP collaboration....

 

Correcto! pump is working when I hook it to battery, BUT sometimes it will work, and sometimes not when I am trying to start the car. I have checked all the wiring, everything is connected together snug, and all wires are solid, no breaks in them. Just dont know.....

 

This is why also I mentioned the ESC (electronic spark control). The ECM won't turn on the fuel pump until it receives reference pulses from the ignition module. You may have a failing igntion module, or pickup coil...

 

replaced harness and relay, all fuses good and im still having the same problem cranks a good 30 to 60 seconds before starting

 

OK, heres the deal! I went out after church today, spun it over ....just for the hell of it. And it fires right up. I heard the pump prime and all. I let it run for a few mins, got in it drove to the store(about a mile away) put some gas in it drove home. And she fired up everytime today.


I am thinking it has a mind of it own!!

 

If it does happen again, try smacking the pump area real hard in the back.