Fuel Pump Issue

[KitKat87]

Hello All!

I have a 1994 Auromatic Explorer w/ 4 wheel drive.

At the end of March I started having issues starting. Replaced the battery, that didn't help, so I dug deeper and realized it was the fuel pump. Replaced that, issue went away.

Fast forward to Oct, she has a rough sounding start, then evens out after 15 seconds or so.

Last week, I ran it way too low on fuel. I just barely made it to the pumps, fueled up, and then she wouldn't start. I wiggled the spark plugs, she started right up, and I drove home. The next morning, she started, roughly, then evened out. Drove about 15 miles heading to work and she shut off while going down the road. Will not restart.

Towed it to my dads, replaced the spark plugs, wires, and cool pack, no love. Still will not start.

I cannot hear the fuel pump priming. Checked the inertia switch, it's good. Checked the relay under the hood, (switched it with a new one), no change.

I'm not sure if they are related, but I will also add a few more things. About a week prior to this (mid Oct) the thermostat gauge in the dash stopped working and the check gauges light stays on. The truck is good on fluid and is not overheating that I can tell. I replaced the alternator in July 2017 as well. She is due for an oil change. I have already purchased the oil and filter, but I don't think that's going to help this issue. I have a large subwoofer wired in as well. This has caused corrosion to the battery posts in the past. I replaced the battery cables and terminal connections in September.

I'm kind of at a loss as to what to check next. Any thoughts?

Thank you in advance, I'm new to the forum. I love this truck and I'm hoping she will last me a bit longer.

 

[imp]

Hello All!

I have a 1994 Auromatic Explorer w/ 4 wheel drive.

At the end of March I started having issues starting. Replaced the battery, that didn't help, so I dug deeper and realized it was the fuel pump. Replaced that, issue went away.

Fast forward to Oct, she has a rough sounding start, then evens out after 15 seconds or so.

Last week, I ran it way too low on fuel. I just barely made it to the pumps, fueled up, and then she wouldn't start. I wiggled the spark plugs, she started right up, and I drove home. The next morning, she started, roughly, then evened out. Drove about 15 miles heading to work and she shut off while going down the road. Will not restart.

Towed it to my dads, replaced the spark plugs, wires, and cool pack, no love. Still will not start.

I cannot hear the fuel pump priming. Checked the inertia switch, it's good. Checked the relay under the hood, (switched it with a new one), no change.

I'm not sure if they are related, but I will also add a few more things. About a week prior to this (mid Oct) the thermostat gauge in the dash stopped working and the check gauges light stays on. The truck is good on fluid and is not overheating that I can tell. I replaced the alternator in July 2017 as well. She is due for an oil change. I have already purchased the oil and filter, but I don't think that's going to help this issue. I have a large subwoofer wired in as well. This has caused corrosion to the battery posts in the past. I replaced the battery cables and terminal connections in September.

I'm kind of at a loss as to what to check next. Any thoughts?

Thank you in advance, I'm new to the forum. I love this truck and I'm hoping she will last me a bit longer.

@KitKat87
I would measure the voltage present right at the battery terminals with a good voltmeter. Initially, nothing "ON", it should read over 12 volts, if less, battery is discharged. If 12.5 volts+ have someone crank engine, turn the key, for about 5 seconds; watch battery voltage, if it drops below 8 volts, something is wrong. Corrosion on the battery posts is due to dirt buildup, corrosion, or very high current drains, or all 3. They must be clean, lubricated (vaseline is good) and TIGHT.

Next, the fuel pump. Did you hear it priming every time you turned the key ON before? But not now? After turning key on and off several times, depress the Schrader valve (just like a tire valve) under the little black plastic cap on the fuel rail. Gas should spurt out. If none, either wiring is the culprit, or the pump itself. Here is how you can check wiring and pump at the same time. Remove fuel pump relay, jumper wire between the + (hot) terminals in the relay socket and the terminal leading to the pump. Most relays have a pin diagram on them. Two will be tied together with a little square or circle, those are the relay coil connections, no help. The other two, usually shown separated, to indicate normally OPEN (no connection), are the two to jumper. Pump will be heard running if it is good, and if you jumper the correct terminals. Remember the relay SOCKET connections are a mirror-image of the relay terminals shown on it. imp

 

[Centaurious]

Ford OBD/OBD2 Codes – TroubleCodes.net

Stop just throwing money at the problem in the form of random parts. Read the codes and if they don't help let us know what the codes are and you will find help here.

 

[KitKat87]

Thank you for the suggestions. I will try these things, and look for a code. I will keep you guys posted.

 

[imp]

Ford OBD/OBD2 Codes – TroubleCodes.net

Stop just throwing money at the problem in the form of random parts. Read the codes and if they don't help let us know what the codes are and you will find help here.

@Centaurious
Judging from the stated symptoms, it seems to me that codes would not necessarily be generated. Doesn't hurt to check, obviously. And, no, it does not pay to "throw" on new parts haphazardly (even if there ARE codes). imp

 

[Centaurious]

"and the check gauges light stays on."

This is why I suggested reading the codes as I guess he means the 'Check Engine' light. My guess would be that wiggling the plug wires is a red herring and an old fuel pump overheated while extremely low on fuel and broke a winding inside. after it cooled the winding made contact again. The next morning it failed again this time completely. This is a Guess.

If we're lucky He has a 542 code and the fuel pump tests bad.

 

[roscoe 0202]

on an obd1 you can run a hot lead to the obdi connector if you look at the connector it is on the short side with four plugs the outside one runs the fuel pump also there is a fusible link blue that powers the relay
roscoe