S$%*!!! Non start! Fuel pump not kicking on

[penske2584]

All these issues started after I put in a higher amp fuse.

Couple months ago the starter failed. Now the fuel pump wouldnt work this morning. No power to it. I tried to click ignition forward without starting and nothing. After a cigarette, damn thing had power again and the Explorer started.

Could too much power to the system cause failure? Or am I dealing with a wiring nightmare? No security lights on dash.

Ive lost my diagrams for my Explorer for the fuse boxes and other relays. Can someone post them please? 1996 XLT 5.0 AWD

 

[koda2000]

fuses don't control the amount of power that flow threw them. you should never install a higher AMP fuse in a circuit. the specified amperage is there to protect the wiring or the devices on that circuit. if you're having an intermittent problem, you've got a poor connection or bad ground somewhere. have you pulled your fuel pump relay and checked for corrosion on the terminals it plugs into? have you swapped the fuel pump relay with one of the other less important ones? all the power in the world will not get something to work if you don't have a ground connection. have you tested the fuel pump and relay grounds? also, remove clean and reinstall you battery terminals.

 

[penske2584]

I have not checked any relays, grounds, connections since the starter issue. I have not tested the fuel pump at all.

As rusty as this Explorer is... mixed with cold... could be any wiring/connection issue anywhere.

Last time they were all good. Relays have some burns on them but I think that is normal over time. I have extra relays just for this issue.

I found diagrams online through the library. One manual said x amp fuse which was written in 1997. The other manual said 5 amp higher written in 2008. Both are specifically for my Explorer.

Might have an issue with the voltage regulator? It wasnt charging the battery until I changed to 5 amp higher fuse. Now it seems its charging too much.

 

[ccm2001]

Did u try reseting the fuel pump?

 

[Turdle]

My best guess is the fuel pump is dying.

 

[koda2000]

My best guess is the fuel pump is dying.

quite possibly. I just got done replacing a dead fuel pump and have another dead one sitting in my driveway. it wasn't a fun job on vehicle with rust, but as I've done it once already, I knew how to do it and what to expect. the hardest part was cutting off the rusty hose clamps from the filler and vent lines. I used my Dremel tool with a thin cutting wheel. worked great. there's always the "cut an access door in the floor" method, but I can't bring myself to do this.

the first verification I made was to spray starting fluid into the T/B. both trucks fired up immediately. then I tested for voltage at the pump and found I was getting power. lastly I tested the ground and found it to be good. so, while it's quite a coincidence to have 2 fuel pumps go out in the same week, it happens. I guess the cold finished them off. fortunately I had the back-up Explorer ready to go. maybe I should have 2 backups... LOL

 

[swshawaii]

Fuel Pump Shut Off (Inertia) Switch and Connector? (Pages 74-75)

If the engine cranks but does not start or does not start after a collision, the fuel pump shut-off switch may have been triggered. The shut-off switch is a device intended to stop the fuel pump when your vehicle has been involved in a major jolt. Once the shut-off switch is triggered, you must reset the switch by hand before you can start your vehicle.

Fuses (Page 381-388)
http://www.fordservicecontent.com/Ford_Content/catalog/owner_guides/96expog1e.pdf

 

[koda2000]

Fuel Pump Shut Off (Inertia) Switch and Connector? (Pages 74-75)


Fuses (Page 381-388)
http://www.fordservicecontent.com/Ford_Content/catalog/owner_guides/96expog1e.pdf

if the issue is related to the inertia switch, you will not get power to the pump. unless someone bumped your vehicle in your driveway, it's unlikely the inertial switch is the problem. still, anything I possible so it's with checking.

 

[Turdle]

quite possibly. I just got done replacing a dead fuel pump and have another dead one sitting in my driveway. it wasn't a fun job on vehicle with rust, but as I've done it once already, I knew how to do it and what to expect. the hardest part was cutting off the rusty hose clamps from the filler and vent lines. I used my Dremel tool with a thin cutting wheel. worked great. there's always the "cut an access door in the floor" method, but I can't bring myself to do this.

the first verification I made was to spray starting fluid into the T/B. both trucks fired up immediately. then I tested for voltage at the pump and found I was getting power. lastly I tested the ground and found it to be good. so, while it's quite a coincidence to have 2 fuel pumps go out in the same week, it happens. I guess the cold finished them off. fortunately I had the back-up Explorer ready to go. maybe I should have 2 backups... LOL

Yup, first cold snap here, sister in law's Mounty said "nope" for 2 days solid.
Same thing here, voltage to the pump connection was good. When it warmed back up she got in it to go to work ( against advice) and it fired right up. The next day we started replacing the pump, using the fuel pump access panel in the floor method because the tank was full.

 

[koda2000]

Yup, first cold snap here, sister in law's Mounty said "nope" for 2 days solid.
Same thing here, voltage to the pump connection was good. When it warmed back up she got in it to go to work ( against advice) and it fired right up. The next day we started replacing the pump, using the fuel pump access panel in the floor method because the tank was full.

yeah, the one I just finished up began occasionally not starting last winter when it was really cold out. I figured it was the fuel pump, but never got around to doing anything about it, as when things warmed up it was fine all spring an summer. I knew that would come back to bite me, but trying to take my daughter's wheels away for 2-3 days wasn't an option and I didn't have the "spare" Explorer then. problem was I needed 2 spares last week.

BTW, I had 3/4's of a tank of gas and a dead battery to deal with from her husband trying to get it started. I siphoned the gas out of the tank. it can be done if you know how.

now i'm looking forward to changing the pump in the other Mounty... hey! at least that one isn't the slightest bit rusty and there's no rush.

 

[drdoom]

I lowered a full tank with the floor jack no problem at all.

 

[koda2000]

I lowered a full tank with the floor jack no problem at all.

as in life, maintaining balance is everything.

 

[SoNic67]

The motor for the pump has two carbon brushes to supply power to the rotor.
Those brushes are pushed to the rotor's collector by metallic springs.
In time, brushes wear out, become shorter and springs need to extend more to make contact.

In cold weather, spring metal contracts and, in extreme case, will not be able to push the shorter (worn) brush to the collector.
That's when the motor will not start cold.

Motor needs to be replaced.

 

[drdoom]

Yes Yoda one hand on the jack one on the tank!

 

[penske2584]

Did u try reseting the fuel pump?

How do I reset the fuel pump?

The motor for the pump has two carbon brushes to supply power to the rotor.
Those brushes are pushed to the rotor's collector by metallic springs.
In time, brushes wear out, become shorter and springs need to extend more to make contact.

In cold weather, spring metal contracts and, in extreme case, will not be able to push the shorter (worn) brush to the collector.
That's when the motor will not start cold.

Motor needs to be replaced.

Explains the temp sensitivity- when it warms up it will work. Im 100% sure it will fail this winter since it gets down to -25F actual temp.

___________________________

Checked inertia first. A OK.
Listened for pump to kick on. Neg.
Reset security. Irrelevant? Maybe not.
Been experiencing lean codes on both banks. Low pump pressure? More than likely.
No weird ground issues such as - turn signals or head lights dropping idle down.
Have always had a bit of rough idle.
It started up after the security restart. Maybe a corrosion starting on wiring or ground? Just took that to warm up? Ignition issue? Transponder issue?

Going to check fuel pressure, amp reading at inertia and possibly continuity of wiring or grounds.

Just guessing the pump is on its way out. Not great timing! Broke as a joke. Hoping my buddy will fix it for now with a used pump. Dont have $ for new.

Any ideas of what I can do to replace pump and keep the sending unit intact? Separate them? If I do buy a new pump, would this be worth doing?

 

[penske2584]

Here is a diagram I went off of that I chose to upgrade from 10a to 15a on the voltage regulator.

Backflash-> Out of the blue, my needle went below. My battery wouldnt hold up to idle then wouldnt start without getting charged. Repeat of dead battery.

Help from you guys, I put in the 15a fuse and charged the battery one last time. It hasnt been an issue but now I have a high reading on the needle for charging. Since this happened... Ive lost a starter and now the fuel pump is going. Related? One person says no so far.

 

[penske2584]

I just put the 10a back in and still high voltage. Battery is from last Jan 13' and should be good. There has to be a ground issue somewhere.

Just want to make it through winter then I will )sell( dump it in spring.

 

[koda2000]

the pump is held to the fuel pump assembly with a clamp. then the only thing holding it in is the hose to the f/p regulator. changing it is easy. getting to it is another matter. if yours is a '96, there is no fuel pressure regulator in the tank.

 

[intelisevil]

"the first verification I made was to spray starting fluid into the T/B. both trucks fired up immediately. then I tested for voltage at the pump and found I was getting power. lastly I tested the ground and found it to be good."

Cranks good but won't start in cold weather? No fuel pressure?

I had this problem last winter. After trying several things just like you did I got a bottle of "HEET", poured it in my tank, shook the Exploder for about 10 seconds and she started right up!

Last week after 10 days with highs in the low 30's and not driving the Exploder, same problem. Again "HEET" to the rescue.

Good Luck!
Dan

 

[koda2000]

"the first verification I made was to spray starting fluid into the T/B. both trucks fired up immediately. then I tested for voltage at the pump and found I was getting power. lastly I tested the ground and found it to be good."

Cranks good but won't start in cold weather? No fuel pressure?

I had this problem last winter. After trying several things just like you did I got a bottle of "HEET", poured it in my tank, shook the Exploder for about 10 seconds and she started right up!

Last week after 10 days with highs in the low 30's and not driving the Exploder, same problem. Again "HEET" to the rescue.

Good Luck!
Dan

You'd have to have a heck of a lot of water in the tank to freeze up the pump turbine. I think you shaking the truck does more to get it running than the Heet. As has been previously stated, when pumps get old the springs holding the brushes inside the motor get weak and wear on the brushes also reduces the spring tension. The cold makes the springs contract even more and the pump doesn't run. Warmer weather or "thumping" the bottom of the tank will sometimes get it to run for a while, but it will fail again - guaranteed. Time to install a new fuel pump, because sooner or later you will not be able to get it running and you'll be stranded.