93 explorer no spark no fuel

[cam68]

i hav a 93 explorer sport check engine light came on lost power now there is no power to the fuel pump or the spark plugs ran a jumper wire to the fuel pump it works checked the fuses, inertia switch and the icm any segestions would be appriciated. thank you Pat

 

[shamaal]

Without the engine code, I'd troubleshoot the fuel pump circuit first. You should hear a 2-3 second whine when you turn the key to run. Apparently you do not.

:
http://www.autozone.com/servlet/UiB..._us/0900823d/80/0b/a9/c7/0900823d800ba9c7.jsp
You want figure 19, shown below. If you want to troubleshoot, put a paperclip into the inertia switch connector (passenger side, under the top of the rug) and read voltage while turning key to run (don't start). It will be +12VDC for 2-3 seconds. Not having the +12 could also set your CEL and prevent spark. If you do not have the voltage, this must be fixed first. Easily changed stuff is the fuel pump relay and the PCM relay.

Let us know how it's working out.

 

[a711112a]

i had this simular problem a couple years ago
it ended up being the ground wires going to the computer
ther are 3 wires comeing off the neg batter termanal the 2 little ones go to the computer check the wires wher they are spliced it should be about a foot away frome the battery mine weer full of green corousion i cut splices out and soderded them together
it started right up

 

[MrShorty]

My first thought when you lose both fuel and spark is to check for power/ground to the main computer, as the main computer controls both spark and fuel pump operation.

 

[shamaal]

IMO, My understanding of the sequence, correct me if wrong, is the fuel pump relay energises, is detected by the PCM, which then continues to energise relay and commence sparking. I could be wrong on the sparking part, I have absolutely no proof. When I finish this kitchen, I'll test my theory by pulling the relay and seeing if I still get spark.

He does get a CEL, which could be the relay failing to energise, so the computer works; but dirty power and grounds do give bizarre indications.

 

[matz162008]

alright now say u have spark but no fuel..... and its not the fuel pump/fuel filter..... the fuel pump works(tested it when it came out of box). we checked for spark and it was there but it still wasnt getting any fuel pressure.. also checked the inertia switch and it was fine.... any help is appreciated

 

[MrShorty]

Is the fuel pump running in the tank?

 

[matz162008]

it runs when its not in the tank and sometimes it works in the tank.... what is a common problem that goes wrong?

 

[MrShorty]

So it runs consistently out of the tank when you "hot wire" it, but not when it's properly installed in the tank? That sounds like something wrong in the wiring to the fuel pump. The best way I've found for testing a DC circuit like this is to get a voltmeter and a wiring diagram. Start at the battery and measure battery voltage, and then work your way down the circuit with the positive lead until the voltage drops (ground the fuel pump test lead in the self-test connector so the fuel pump relay should be closed). If the voltage drops before you get to the fuel pump, the problem in the circuit is where the voltage drop is. If the problem doesn't show up on the power side of the circuit, dont' forget to check the ground side of the circuit for bad connections/ground.