fuel problem, electrical I think

[LOCOprobe]

Well its been a while since I have posted on here, basically because I havnt had any money so i hate looking at stuff I cant buy and other trucks that i cant afford to make mine look like haha.

but now I have a problem and i am really hopeing someone on here can help me.
now I know ALOT about cars, and use to build fast cars and have done alot of motor builds etc etc, so you guys dont have to go into too much detail lol.

let me start by saying I have a 2000 explorer AWD 5.0 with 112k on it

anyway, I am driving down the road the other day and traffic starts to speed up so I give it some gas to speed up and nothing. truck cuts off so I pull over into a parking lot and try to start it back up and it just keeps turning over but wont fire.
I get it to fire once but it studders and wont stay started. So i know from the start that its prob. fuel.
I check the bleeder valve on the fuel rail and let the pressure off of it and try to turn it over again and then check the rail again and no pressure, so I am getting no fuel pumped to the motor.
In my mind its the fuel pump.
So I get it towed home and check all the relays and fuses, all are good (unless I am missing something, I dont have a haynes manuel for this truck) I also check the fuel cutoff switch, it wasnt tripped.

So I drop the tank and pull the pump, jumped it and the pump still worked, but just in case I got a new pump, put it in and still nothing.
i take the gas cap off and put it back on and make sure its sealed because that can cause stuff like that sometimes, still nothing.

so im thinking, well if the filter is stopped up it would keep pressure on the pump and not make it run. so I pull the line off the back of the fuel filter (comeing from the pump) and turn the car over and no gas comes out, pumps still not working, so its not the filter.

I pull the vac lines off the reg, because if its that, sometimes you can trick the comp. long enough for it to pump some gas, still nothing.

I then try to check to see if I am getting power to the pump with a voltage meter, and im getting no power. Now it was hard to get the tips of the voltage meter to touch the contacts from the pump, so I am not 100% sure that I was making contact, but I think I was. it also had no continuity (sp?)

I am pretty much at a lost right now, and really need some help. Ive never had to work on this truck so i dont know all the little ins and outs of the truck.

any help from you guys would be AWSOME. thanks alot

 

[Turdle]

ok
Switch the key to on-does the check engine light illuminate?

Relays shown here-

http://www.explorerforum.com/forums/showthread.php?t=180814&highlight=power+layout

 

[BrooklynBay]

Check ground connections. Your fuel pump won't turn on if the PCM has no power as Jon mentioned. Jump the relays with a piece of wire. The pump should run.

 

[LOCOprobe]

the check engine light does come on when I turn the key on. also the PCM fuse is fine.

what else should I check?

 

[budwich]

go to some connector along the pump electrical route.... probably just after the inertia switch... where you know you can get a good connection. Unplug the connector and measure the resistance towards the pump. There should be some. IF there is no resistance (ie. short) or its very high (ie. megaohms -> open) then you have wire problems to your pump.

 

[Turdle]

Checking the voltage at the pump is tricky-usually requiring 2 people. You will only see 12v at the pump for 1-2 seconds after the key is switched on, then it will drop.

I would double check the relay, and the inertia switch

 

[BrooklynBay]

Bypassing the relay applies full battery voltage to the pump. It wouldn't shut off after a few seconds since the computer's output is bypassed. This would be the easiest way for one person to check the wiring.

 

[LOCOprobe]

well I have tried switching out the relays and still nothing. I have tried checking power at the pump with 2 people, him turning the key and me checking for power and I have nothing.

I really dont get it. the truck isnt old enough to be having wireing problems already lol. its stock haha.

I will try jumping the relay tom. though. I dont remember how the prongs looked on the relay but if there are more then 2 which ones do i jump?

 

[BrooklynBay]

There are 4 wires. The 2 thick wires are the power wires you should jump. The thinner wires are only for the coil. Check those with a test light to see if there is electricity on the coil when you turn the key to the accessory position.

 

[LOCOprobe]

There are 4 wires. The 2 thick wires are the power wires you should jump. The thinner wires are only for the coil. Check those with a test light to see if there is electricity on the coil when you turn the key to the accessory position.

ok thanks, I will check that when i get home from work today

 

[LOCOprobe]

ok i would just like to start by saying I am an idiot.

so today I keep checking power places and such, and I decide to check the power going to the fuel cutoff and I go to unclip the wires and the clip was pretty much just hanging there. I am guessing whoever sat there last hit the clip and unplugged it.

I plugged it back in and the truck started right up. I hate when its something simple after you have already done harder work trying to figure it out haha.

thanks for all the help guys

 

[Turdle]

Well, now you know your truck a bit better--

Good job finding the problem-

 

[CDW6212R]

I just ran across this, those inertia switches are easy to damage or disconnect there.

 

[LOCOprobe]

lol yeah I learned more then I needed to on the truck haha.

and yeah that was not a very good place for the Fuel cut. most the time its in the back. most the cars I have built I get rid of the fuel cut anyway

 

[BrooklynBay]

Thanks for the update!