fuel relay 91 explorer

[jenglish007]

long time reader first time poster, I have read all the threads i can find on the fuel relay and fuel pump problems but I have a simple question for all you ford guru's that seem to have most of the answers, First of all my fuel pump will not prime, i checked the voltage on the inertia switch, it is good. I checked all my connections at the relays they are good, but when I bypass the fuel relay the pump seems to be priming or running (i can take the gas cap off and hear what sounds to be a sloshing sound). Does this mean the relay is bad? and if so do i need to go ahead and replace the eec relay (i do not now how to test or bypass it)? If i jumper across the fuel relay would the engine start? I just finished replacing all the upper gaskets in the engine, now i am not getting any fuel pressure or power to the pump unless i jumper the fuel relay. Any help would be appreciated.

 

[BrooklynBay]

Welcome to this forum! If your check engine light does not come on when you turn the key, it means that no power is going to your PCM (computer). If the computer will not turn on, your fuel pump will not turn on either.

 

[bdfrenchy]

might wanna ck the emergence cut off switch on the trans. hump firewall passenger side under the carpet I had to replace mine it shuts off the gas to the motor

 

[jenglish007]

ok here i am again

inertia switch tested good, and i do have a check engine light. I purchased a new fuel relay and fuel filter this morning and i am going to try that this afternoon. When i turn the key on i hear a click and then 2 seconds later another click like it is cutting on and then off.

 

[Maniak]

When you bypassed the fuel pump relay.. Did you check to see if the PCM was sending 12V to it.. If it was, then its the fuel pump relay.. If not then the PCM isn't sending it power, which could be the EEC relay (more likely than a blown computer)

~Mark

 

[jenglish007]

here i am again

you are talking about 12volts at the pump right? I did not check the voltage at the pump, but i will. I will try the new fuel relay first and If that does not do it, I will cross the relay out again and check the voltage at the pump. Will there be 12v on one of the wires or on all of them. The pump was making noise when i crossed the relay out, It sounded more like a mixer than a whine or steading noise, but there is only about 2 or 3 gallons of gas in it. do you know how much a eec relay cost?

 

[Maniak]

If I remember correctly.. The Fuel pump relay has two 12v signals.. One is the fused 12V that is sent down the line and the other is the signal voltage from the PCM that says to turn on the fuel pump.

When you said you jumped the fuel pump relay I'm assuming you took the 12v source and sent it down the line. You should also check if there is 12v at the signal side. The 12v signal from the PCM is was turns on the relay and allows the 12v source to go down the line.

~Mark

 

[jenglish007]

here i am again

I do know that there is 12v at the relay, and then there is a second click about 2 seconds later but i do not know from which relay that click comes from, and i do not believe that the 12v is there after the second click, i will have to check and see i cant remember, i have slept since then! ha.

 

[jenglish007]

ok, i replaced the relay and same thing, turn key on "click" and two seconds later "click" no power to fuel pump. does anybody know how to get the fuel lines loose from the fuel filter, i was going to go ahead and change it anyway.

 

[jenglish007]

ok after many, many try's i am not getting anything to the fuel pump, i have 12v on one side of the fuel relay, i am getting a momentary 12v at the inertia switch, then when the second click happens i loose the voltage. I believe the fuel pump is good, but i cannot get any power to it to test it. any help would be greatly appreciated.

 

[shamaal]

ok after many, many try's i am not getting anything to the fuel pump, i have 12v on one side of the fuel relay, i am getting a momentary 12v at the inertia switch, then when the second click happens i loose the voltage. I believe the fuel pump is good, but i cannot get any power to it to test it. any help would be greatly appreciated.

If you have +12 volts at the inertia switch, the pump should come on, this will last 2 to 3 seconds. This is the whine you should hear. If you do not, the pump or the wiring between the inertia switch and pump is bad.
The check engine light may or may not be related. Troubleshoot one problem at a time.

When the engine is started the pump will come on full time and there will be a steady +12 VDC. The 2 to 3 second momentary signal brings the fuel line up to pressure and routes a signal to the PCM for pump relay closure confirmation.

See fig 7 in the drawings at:
http://www.autozone.com/servlet/UiB..._us/0900823d/80/0b/a9/c7/0900823d800ba9c7.jsp

You can also measure the resistance at the disconnected inertia switch to ground. I can't remember the correct resistance right now, and it's raining out. It should be low. It should not be open, again the pump is bad or the wiring at the pump connector is bad.

 

[jenglish007]

here i am again, and again

i went ahead and pulled the gas tank, i have a feeling the pump is bad. Anybody have any idea how to get the fuel lines loose, they look like the duck billed connectors in my chiltons book, but i cannot get them loose. Is there a trick i just dont know about? when i get them loose i will go ahead and replace the pump, i cannot get a whining noise from it, just a gurgaling sound. all help will be appreciated.

 

[shamaal]

1. Relieve the fuel pressure! Put a rag over the Schrader valve on the fuel rail and depress until no pressure.

2. The special tool to work on the fuel connectors can be had as a loaner from the autostore (Autozone). Some people use the plastic ones, others use the metal ones. Mine were stuck together regardless of the tool used and I had to pull the spring out with a jewelers screwdriver and a needle nose pliers. The replacement springs can be had at Autozone.

Avoid the urge to rip or saw apart. The lines are expensive to replace and I wouldn't recommend a rubber replacement.

 

[jenglish007]

here i am again

dont worry about the fuel pressure, there is none, the pump has no power and i had already relieved it while i was checking for fuel pressure earlier. I asked at autozone yesterday and the certified guy said you did not have to have a tool, I will take care of that this afternoon, i will try oreilly's also. thanks for the help, after i get the new pump in and all back together i will let you know if it worked or not.

 

[shamaal]

Not to disagree with the Autozone guy, but on my 91 I needed a special tool #10 in this informative thread shows a picture of the plastic and metal tools.

http://www.explorerforum.com/forums/showthread.php?t=100047&highlight=fuel+pump+tool

Good Luck

 

[jenglish007]

still no start

well, i spent a couple hours changing out the fuel pump and to no avail. although i do have fuel at the engine now it still will not start, i have fire (first thing i checked) it seems to be in time but it will not hit a lick. I went ahead and replaced the fuel filter and fuel relay while i was at it. Oh, i bought a tool and the lines popped right off, go figure, anybody have any ideas now?

 

[BrooklynBay]

Did you check all of the wires (not only one) to see if there is a spark going to the spark plugs? You could have a bad coil, ignition module, cam, or crankshaft sensor, etc. First test the sensors. Put a breaker bar on one of the pulleys, and turn the engine over manually (by hand). Leave your electrical system turned on with the key in the ignition. You should hear the fuel pump cycling everytime you turn the engine over.

 

[jenglish007]

I wonder if the injectors could be flooding the engine, It has set up for a while, I think i will pull the plugs tonight and let it set, then pull the fuel pump fuse and turn it over a few times before hooking it back up, that would let me know if it was flooding or not. Does the PCM control the injectors? I dont believe it could be the coil pack because I got it to run on starter fluid for a few seconds on Sunday and it sounded fine, After everything I have done know and replaced so many parts, getting fire and fuel, it has to be something simple at this point. Thanks for everyone's help so far and I look forward to driving this explorer for the first time very, very soon.

 

[savagefan]

Have you checked all the fuses?

 

[shamaal]

If the pump has been running for any length of time, there could be an unacceptable amount of gas in the cylinders. Your plan to pull plugs is sound. Yes the compuer controls the injectors.

Good Luck!