fuel pump fuse keeps blowing

mandkole · Sep 23, 2014

cutthroatxxx said:
The fuse only blows when you start driving.I just got done messing with it heres a few things Ive noticed not sure if any of this matters but I have the hose on the back of the fuel bowl but when I open the drain valve the fuel shoots out very hard if thats normal idk.Also the element in thr bottom of the fuel bowl was bent up I couldnt get it to lay flat so I snipped it off right before the black wire?That it connects to.Now it will not start@all Idk if its related to that or not.I only visually inspected the wiring Im going to try to get a volt reader.Unfortuantley Im FAR from town so Im pretty much left to fixing this.myself

Holding pressure when off? If so, that is not normal... When you did the tank mods, did the return get set up correctly? Is there pressure in the tank when you pull the filler cap? Im not totally familiar with a stock SD 7.3 fuel bowl setup, but sounds like the pump is deadheading or pressure backing up in return.

Heater delete is fine but unplugged is all thats necessary.

Arisley · Sep 23, 2014

My truck will hold fuel pressure for quite a while after shutting down the engine. There is no pressure release valve, that I know of.

mandkole · Sep 23, 2014

Ok, maybe its normal to have pressure in the bowl on an SD after shutdown. In my truck fuel pressure will stay up on the gauge after shut off but if I was to crack a fitting it wouldnt be under pressure. On the OBS, there was no pressure in the bowl after shutoff.

cutthroatxxx · Sep 23, 2014

I belive so the only thing we really did was remove the mixing chamber & duckbill added the compression fitting&new pick.up foot left the other metal tube bare&installed it then hooked all the fuel lines back up.I hope I didnt miss anything.I.used the diesep.innovations kit

cutthroatxxx · Sep 24, 2014

When I did my tank mod the diesel innovations kit says nothing about.modding the return line so I just left it how it was after I removed everything from.it.Could that cause a problem?I really don't wanna drop the tank.again if I don't have to I'm criped that bs took me forever.

Stroker04 · Sep 24, 2014

When was the last time you replaced the fuel filter? A restriction will cause the pump to draw more amps..

cutthroatxxx · Sep 24, 2014

Just the other day

Stroker04 · Sep 24, 2014

May want to try disconnecting a fuel line, and turn the key on and see if it will blow. Just make sure you have a bucket handy.

cutthroatxxx · Sep 24, 2014

Its only blowing once I drive it for a minute or so

Arisley · Sep 24, 2014

Are you sure it's the fuel pump fuse? If you pull the inlet line from the pump, are you getting free flow from the tank? It is actually pretty common for the line to get pinched when reinstalling the tank.

Sent from my truck while eating, adjusting the radio and passing a Mustang sideways.

ghohouston · Sep 24, 2014

are these parts store pumps, or ford (bosch) pumps? if it truly is the fuel pump fuse blowing, and only happens while driving, you either have wiring that starts moving once you are driving down the road, or the pump is being restricted somewhere, causing it to pull too much current, thus, blowing the fuse. have you checked fuel pressure under load?

cutthroatxxx · Sep 25, 2014

ghohouston said:
are these parts store pumps, or ford (bosch) pumps? if it truly is the fuel pump fuse blowing, and only happens while driving, you either have wiring that starts moving once you are driving down the road, or the pump is being restricted somewhere, causing it to pull too much current, thus, blowing the fuse. have you checked fuel pressure under load?

I have 3 pumps on hand 1 is a bosch I got from rock auto,1 I got from the parts store 1 is from ford someone gave me.I have pulled the line from before the pump&it ran out without a problem & then pulled the line from the front of the pump&cycled the key it shot fuel out just fine.

cutthroatxxx · Sep 25, 2014

ghohouston said:
are these parts store pumps, or ford (bosch) pumps? if it truly is the fuel pump fuse blowing, and only happens while driving, you either have wiring that starts moving once you are driving down the road, or the pump is being restricted somewhere, causing it to pull too much current, thus, blowing the fuse. have you checked fuel pressure under load?

Arisley said:
Are you sure it's the fuel pump fuse? If you pull the inlet line from the pump, are you getting free flow from the tank? It is actually pretty common for the line to get pinched when reinstalling the tank.

Sent from my truck while eating, adjusting the radio and passing a Mustang sideways.

Flows fine & yea Im 100% on the fuse.Idk s@!+ about.wiring only tool I have for it is a test lite.I do.paint & autobody metal fab stuff if its vacumm or electrical I usually farm it out.I have a fella coming by today from a shop down the rd I have a full shop so hes gonna.work on.it here but its not cheap plus having 2 pay him extra for the housecall.He has a quality scan tool &I will ask him to check the fuel pressure.I have no idea how to can anyone tell.me.what I need?Moneys real tight right now Im on 2 full restorstions Im talking interior,motor,brakes,trim,exhaust,tired wheels etc etc & Im far behind about 3 months & dont get the $ till Im done so I dont want to have him doing things that dont need done.So as of now I.figure run codes again,idk if you can check fuel pressure with a scan tool but his cost about 4 grand so if you can Im sure his will,then have him check from I belive its the fuel box to the relay to the interia switch to the pump?I wanna do the 50cent mod but noway 2 get 2 the parts store to buy valve cover gaskets right now.Anybody has anymore suggestions on what all I should have him do Id apprecite it.
-------------->>>>>AND...I wanna say thanks fellas for trying to help me figure this out.This is my 1st diesel &Ive had it for 2 months now&Id like to be able to enjoy it.Took me along time to get 1 I had a lifted ram gasser & thought about a cummins but I hated the suspension & liked the room of the fords for the kiddios & though I like the power of the cummins.I have a g-body thatll smoke any cummins in my county just needs a ne2 tranny &the sd seems like itll stick around 4 awhile & in the past yr Ive done.rockers,cab corners etc on 13 cummins.I had 1 sd come to the shop&his rot was his fault from not fixing a leaky window.Anyways Im ranting I wanted to say thanks

cutthroatxxx · Sep 25, 2014

Btw my icp hwe oil in it.Unplugged it runs no.diffrent but the lite comes on I.will replace but that should have nada to do with the fuse.I wae thinking tps.since.it happems when I drive it.But then again I can rev it & it wont blow till I drive it for a min or two.Right out the gate its really sluggish also.

mandkole · Sep 25, 2014

Were not getting the full story here. Did the truck run fine before the prepump mods were done?

Its not the pump(s) and I doubt its wiring.. As gho said, it kicks the fuse when demand increases and causes a load on the pump. Normally, demand is easier on the pump unless there is a restriction.

The mods should not affect pump operation unless they were installed wrong (sucking a lot of air or have a return issue in the tank). Cracking the fuel bowl drain and having fuel blow out under pressure when engine off makes no sense either. Can you watch the fuel in that little filter that the DI kit comes with?

Stroker04 · Sep 25, 2014

mandkole said:
Were not getting the full story here. Did the truck run fine before the prepump mods were done?

Its not the pump(s) and I doubt its wiring.. As gho said, it kicks the fuse when demand increases and causes a load on the pump. Normally, demand is easier on the pump unless there is a restriction.

The mods should not affect pump operation unless they were installed wrong (sucking a lot of air or have a return issue in the tank). Cracking the fuel bowl drain and having fuel blow out under pressure when engine off makes no sense either. Can you watch the fuel in that little filter that the DI kit comes with?

This..there has to be some kind of restriction if the pump keeps drawing excessive amperage

cutthroatxxx · Sep 25, 2014

mandkole said:
Were not getting the full story here. Did the truck run fine before the prepump mods were done?

Its not the pump(s) and I doubt its wiring.. As gho said, it kicks the fuse when demand increases and causes a load on the pump. Normally, demand is easier on the pump unless there is a restriction.

The mods should not affect pump operation unless tey were installed wrong (sucking a lot of air or have a return issue in the tank). Cracking the fuel bowl drain and having fuel blow out under pressure when engine off makes no sense either. Can you watch:grouphug: the fuel in that little filter that the DI kit comes with?

No it didnt run fine before the mods.I bought the truck it was a ford service truck had sat for a yr.I.know nothing about diesels so I took a fella with me who supposedly knows about these aw hes had atleast 6 for wreckers.When we started it she was slow out the gate but picked up speed.He said that was normal I had no idea if he was right or wrong.Got her home next day took het out slow to go but once speed picked up she was good.She bucked twice.Thinking it was old fuel took her home.drained fuel looked fine.awhile later took het out she died got het home blown pump fuse replaced pump ran took her out same thing happened.Came here pump mods is what everyone said to do so I did same issue only b4 fuse blew soon after u fired her up.And yes fuel shoots out of bowl like a volcano.The hose coming off of bowl was.blocked so*I pulled it off but when u open valve woosh!And yes u can see fuel swooshing through the inline.filter.Im lost cant.find any bare wires.Im sure Ive left nothing out of my story.

Arisley · Sep 25, 2014

The fittings between the fuel lines and the heads are little one way valves. There is a little screen in there. Those may be clogging up, I have seen it happen before.

Pull them out, bore them out with a drill bit, make them just a straight through fitting. Make sure they are super clean before reinstalling them. Any little metal shavings left in there, will go directly through the injectors. Not good.