Fuel pump problems

[turbobull]

i have a friend with a 2000 ranger that wont start. he was leaving for school one mourning and he said it turned over but never started. i know the fuel pump is not working because i cant hear any noise when i turn the key on to pressurize the system, and there was no pressure when i poked the schrader valve with a pen. so i bought a pump from advanced auto parts and plugged it in while the tank was still on the ground just to make sure it was the pump but that one doesnt work either. so i did what i should have done before buying the pump from advanced, i checked the fuse, relay, and the inertia switch but those looked flawless. i have no idea what else it could be. has anyone experienced this?

 

[Mutant Pony]

Yeah. You need to check the system out with a test light(or something similar). You will need two people, one to run the tester and one to turn the key. Start from the tank and work your way forward until you find where you lost power. I've had inertia switch failures on older Rangers quite frequently. I've seen relays go bad on ALL vehicles. It could also be in the main computer, a bad ground, ignition system, etc. The first thing you need to do is find out where you lost power.

 

[turbobull]

aight. im headin over to his house now so ill post what i find tomorrow. thanks.

 

[Mutant Pony]

Find anything yet?

 

[turbobull]

sorry bout the delay i couldnt work on it for a week cause my friend who owns the truck had some family problems but i was over there last night and i found that the old fuel pump works fine so it has to be and electrical problem somewhere cause there is still no power to the pump when the key is turned on. i was unaware that there were fuses on the drivers side of the dash between the door jam. i checked those fuses and i found fuse 19 was blown. it was a 25 amp fuse. so i stuck a paperclip in it to bypass the fuse and there was still no power to the pump. i checked all the relays in the power distribution box and they all checked out however i do not know exactly which relay controls the fuel pump or if the fuel pump relay is even in the power distribution box. can anyone tell me exactly where the fuel pump relay is located? and what does fuse 19 go to? also can someone tell me how to test a relay cause im not certain that im doing it right? and just to verify the power to the fuel pump is delivered through a pink wire and a black wire (the two middle wires on the 4 prong side of the connecter to the pump)?

thanks,
Korey

 

[Earl43P]

PM sent - I need to know which engine it has so I can send you the schematic (after you reply to the PM with an e-mail address).

Fuel pump relay is #5 in the underhood junction box.

You can swap it with one identical to it nearby (7= horn, 3= wipers, 8= foglamps, etc.)

You can jumper the inertia switch (DG/YE to PK/BK) but if the Inertia switch was tripped, you'd have a Fuel Reset light illuminated in the dash.

You should also check the PCM Power diode, the PCM Power relay (#4 UHJB), Fuse #8 = PCM Power, and of course, Fuel Pump fuse #9, 20A.

Any one of those can cause fuel pump to not run.


YES, PK/BK is the power wire to the fuel pump at the tank connection from the inertia switch. Power is DG/YE on the supply side of the inertia switch.

If you make sure that the solid RED wire in the UHJB has power with the key on, that is a quick way to CONFIRM that the PCM Power Diode, PCM Power Relay and PCM fuse 8 are all good. That red wire goes a lot of places, but the one you are concerned with is, it powers the relay coil for the fuel pump relay. So if the Red wire isn't powered, no fuel (among other things).

At the fuel pump relay sockets (fuel pump relay removed), you will find one socket ALWAYS powered (from fuse 9). You will find another socket that is only powered with the key on. That one is the coil of the relay. It is also the one that if power is THERE with the key on, the PCM Diode, PCM relay and PCM fuse are good (same red wire).

Hope all that helps.....

 

[turbobull]

thanks. that helps alot. ill try all that tomorrow. it is a 2.5l

thanks again,
Korey