Help! Troubleshoot 'No Start' '94 4.0

[Ed Tapanes]

AIIGHHHH!! Finally finished up the ball joints, button everything up, run inside to change out of my grease laden clothes in anticipation of a victorious test drive and when I go to start the Explorer, it just cranks away without starting. Son of a B*TCH! Okay, I figure I pounded away on the spindle and the ball joints to knock 'em loose, so I might've knocked something loose or askew. It turns over just fine, haven't checked to see if I'm getting fuel or spark yet. I've done extensive work on older vehicles (non-computer) and have always tested for spark by grounding a spark plug wire to the block or exhaust manifold. A friend told me that was a sure way to fry the computer. WTF?! Is this true? If so, how does one test for spark? Also, where the hell is the fuel rail in this thing ('94 Sport 4.0/auto)? I was looking for the schraeder valve to at least check for fuel pressure but couldn't find it. A quick look in my Chilton's proved quite dissapointing. I know, I know, get the f***ing TSM.
SO, what is the collective's suggestions or guidance for getting this thing started back up?

TIA,
Ed T.

 

[flyguy]

Sounds like you broke it. Other than that I have no idea what could of happened.

Nick

 

[TPLYNCH]

Ed,
Do a search for fuel pumps. I know your questions have come up before. You may want to make sure the automatic pump shutoff wasn't accidentally activated. Exact location of the reset button should be in the owners manual. Sorry I can't be more specific about where it is. Pulling a plug to check if you are getting a spark will not fry the computer as far as I know.

 

[98/92EB]

Agree with TPLYNCH, the most likely reason is your shut-off switch. On my 98, the fuel reset indictation light would also then come on in the instrument cluster. The shut-off switch intended to stop the electric fuel pump when your vehicle has been involved in a substantial jolt.Wow, you are strong... On my car, it is located in the passenger’s foot well, behind the kick panel.

 

[Ed Tapanes]

Thanks guys, I'll check the inertia switch tonight.

BTW, it's surprising the amount of strength that you can muster while battling evil ball joints...

 

[flyguy]

Ah, the switch on my 94 is passenger side.. but closer to the middle if my memory serves me right.. (which it never has)

Nick

 

[Ed Tapanes]

Okay, found the inertia switch (immediately to the right of the tranny hump hidden behind the carpet on the firewall) but it was not tripped.
Tested for spark and it has spark. Checked for fuel at the schraeder valve and not a drop. Checked the fuse for the fuel pump and it was fine. SO, it has to be either the high pressure pump on the frame rail or the low pressure pump in the tank, right? Obviously I'm hoping it's the easily accessed high pressure pump, but with my luck I'm imagining that it'll be the in-tank pump.

Any quick and easy things I should check before delving into the pumps?

Thanks all for your help so far.

 

[TPLYNCH]

I don't know about quick and easy..... that flew out the window with the relay switch not being thrown. If you turn your key to on, but stop before turning all the way to start, do you hear a whine? You should hear the fuel pump in the gas tank priming before you turn it over. If you don't, then it's not getting juice or is broken. If it does, then you may have a blockage in your fuel line. I can't help with the fuel rail pump. Don't know anything about it unfortunately.

Good luck.

 

[flyguy]

Hmm.. you might want to refer to my first post about it being broken...

Nick

 

[Ed Tapanes]

Nick,

While I certainly appreciate your incisive diagnosis, I don't concur with your conclusion. It is _not_ "broken" but rather, certain parts have failed to work within design parameters, requiring readjustment or replacement. But certainly not the 'b' word...

 

[98/92EB]

As Tor swings his mighty hammer at the Evil Balljoints....
oops: Okay, assumption now is no fuel to your honey.
1. Remove fuel pump relay and check the voltage first.
2. %#$ it was okay? Check that the camshaft postion sensor is connected (Powertrain Control Module will ground the fuel pump relay for 3 seconds as long as the CMP sends a reference pulse.
3.&$#@% Check the PCM relay.
4.%@$#@ mumble mumble... Check PCM power relay
5. $#@% Assumption now is all relays checks out. Check if voltage is reaching your fuel pump. If yes, check for continuity to ground at two terminals of the fuel pump harness.
%#$@$ Still broken? Flyguy might be right...the B word.

 

[flyguy]

Hmmm.. do you have gas? heh.

 

[Ed Tapanes]

Okay, how do I check for voltage at the relay? Am I checking the relay itself for continuity?
Are the PCM and PCM Power relays clearly marked?
Should both pumps be getting juice at KOEO?

Hehe, ayuh, it has plenty of gas.

Thanks

 

[98/92EB]

Didn't wanted to run this thread too long or eat up Rick's server space, Ed. Best thing to do is get hold of a Haynes or some other repair manual for the pictures, locations, wiring circuits. Since if car worked right before you did the joints, assumption is still that you somehow caused an opened circuit. (A cheap code scanner might simplify your tasks). If you hear a whirring sound from the opened fuel filler opening at the first 2 seconds when the ignition key is at the On position, it means your fuel pump and relays are working.

 

[Ed Tapanes]

Gotcha. Thanks for the help guys.