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How To Change a fuel pump / fix a car that dies on corners

66470 Views 121 Replies 54 Participants Last post by  marclar
You will be working with the fuel system of the vehicle. Since gasoline is explosive there is always the chance you can blow yourself up, or start a really nice fire if you don't follow common sense. This is the same commen sense they were supposed to teach you in grade school so let's hope you learned it well.

It's not my fault in any way if you blow yourself up, break stuff, or start a really nice fire.

Locate the fuel cut-off switch in the trunk of the vehicle, and flip the tab up so it is in the off position. Start the car and let it run until it dies. This should only take a few seconds.

Disconnect the battery

Remove your back seat

Undo the fuel cap to relieve fuel tank pressure

Remove the access cover and undo the fuel pump harness

Pull out the tabs and disconnect the fuel lines. Tie them back. Keep track of which one is which or you will have issues when you go to start the car again. Clean the area around the locking ring.

Using a hammer and a non-ferrous punch (aluminium-hardworrd-copper or anything tough and non-sparking), undo the locking ring turning counter clockwise. Remove the pump from the tank. Be careful to not allow any debris to fall into the tank. It will require some wigglage to get the pump out around the fuel level sending unit as well. Take your time and be patient, it does come out.

The entire sending unit.

To change the fuel pump is quite simple once you get the strainer off as it is in there quite hard to remove. After that just slide the pulsator assembly up on the tube, disconnect the wires and replace with a new pump.

The fuel pulsator mod, why the car dies on corners

If your car:

-Sputters with less than 1/4 tank of fuel and is fine anyother time
-You experience a huge loss of power or your car dies when taking on-ramps/exit ramps or sharp corners

...than this mod is probably for you.

You can see from this end pic how the grey seal isn't sealing too well. What happens is as the pump moves back and forth in the tank it distorts these seals causing fuel pressure to bleed down. Once it gets bad enough it will bleed enough pressure that you feel anything from a lack of power to a complete stall. You can see in the pic above how I originally had a zip tie wrapped around the fuel pump to restrain any excess movement. With the movement gone the car ran much better, but not as good as it was about to.

I went to my local parts store hoping to easily get a replacement. I managed to get a Carter part number, but the part is discontinued. Ford will only sell you the entire sending unit. Seeing as how I just shelled out some coin on a new fuel pump thinking it was the problem, I was not about to spend double that on a sending unit from Ford.

The solution, hose!!!!

The pulsator acts as a vibration damper, basicallly an acumulator for the fuel system to help reduce shock loads on the pump. Seeing as how the fuel system is already equipped with a pressure regulator which also helps reduce shock, it seemed kind of redundant and I could find no other reasons for it being there. I couldn't seen any harm in replacing it with a piece of hose, so I did.

You have to be careful what kind of hose you use. Notice the yellow tinge/coating on the hose. This is because it is wax impregnated fuel injection hose. The wax helps repel the gasoline and extend the rubber hoses life while in the tank. Regular rubber hose will degrade or go "skunky" after a few months when left submerged in fuel. This is 5/16" fuel injection hose rated at 65psi, more than enough for stock applications. If you're running higer fuel systems pressures than that, you're probably more than smart enough to get a higher pressure hose for your application.

A couple of clamps, and in she went. Micky mouse zip tie removed.

Installation is the reverse of removal. Once you get the sending unit in and hooked up, you may want to hook the harnesses, fuel lines, and battery back up. Reset the fuel cutout switch and take it for a drive without the access panel or rear seat in. This will give you a visual indication if the tank ring seal is leaking or not. If it's good and dry, with the car off disconnect the harness, re-install the cover and rear seat and your good to go. If it leaks, re-check the tank seal to ensure it is seated properly, it can be trying to put in. If everything appears fine, you may either need a new tank seal or new locking ring.

I have had this in my car in excess of a year and a half time with no problems. This includes exposure to the occaisional bottle of injector cleaner. Also, my car sat with the same tank of fuel (with stabilizer) for 4 full months, probably the worst thing you can do with fuel components is to let them sit for long periods of time with the same degrading fuel. Not a single problem to date, this car runs like it was new :wink:

Matt 8)

EDITED to add additional reference link to a discussion, and repair of same fault.
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I would cut the pigtail and all off the JY car, cut the wires back, figure out which ones are hot and ground, and touch them to the appropriate battery terminal and see if it buzzes or makes any noise at all. There's really not a real way to tell besides doing the aforementioned, or installing it. That is REALLY one of those things you want to get new....
every car i seen at pull a part has no battery so what i would do to test it before purchase is to bring a 9 volt battery with some wiring. some people will use this to check the shift solenoids in their transmission, i would too.
I have brought my jump start pack to test things like window motor operation before purchase.
Wouldn't you be in your own car? I drive my car down thru the yard, went muddin last time I went though, it was SUPER slush from the snow the day before. Twas fun though! Looked kinda sick flinging rooster tails with the front end. One of those many times I wish it was AWD :(
HAHA, My local PnP is not a drive-in lot and if it was, I sure as heck wouldn't, or rather, couldn't drive this through it. This is a road beast; it does make me miss my stock winter beater though. I miss the ride in general. It has been put away for the season and it isn't ending fast enough, LOL.
yesterday i was going to replace the airtex fuel pump with a bosch and found out that one of the parts that comes with it is a hose to replace the pulsator. so no matter what pump u r gonna be using to replace the dead or poorly working one, u need to replace the pulsator. it seems to loose it's ability to seal properly when u remove the original fuel pump.
juggalo said:
yesterday i was going to replace the airtex fuel pump with a bosch and found out that one of the parts that comes with it is a hose to replace the pulsator. so no matter what pump u r gonna be using to replace the dead or poorly working one, u need to replace the pulsator. it seems to loose it's ability to seal properly when u remove the original fuel pump.
So did this work for you- Cause I changes the fuel Pump- the Little hose, Fuel Filter- and Im still getting the lagging and turning off issues??>>>
Water floats on top of fuel.

I searched all six pages in this thread and there is no mention of H²O.

So I'm curious, has anyone with this issue, ever tried completely draining the tank ?

Theoretically, having water in the tank wouldn't be an issue until the fluid level gets low enough for it to reach the sock; which is four to six gallons.

I've never had the issue but the sock (at least in mine) is positioned on the driver side, and reaches up to the top of the round baffle that the pump is tucked within.

By the way, anyone know or understand how the float works, despite still being completely submerged half-a-tank or six gallons ??? EDIT: Nevermind. The phrase "specific gravity" popped into my head and that got me Googling.

EDIT: Got that backwards. Fuel floats on water.
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Water does not float on top of fuel. It lays at the tanks lowest areas. Modern fuels that contain some ethanol actually have the ability to absorb quite a bit of water over time. This is one of the reasons that new gasolines sour so quickly.
Yep. Quickly realized that and edited in a correction.

That bit about water absorption is interesting. I guess you mean "gasolines sour so quickly" when stored in an open environment. Finite amount of air in a sealed container or sealed fuel tank with proper functioning evap system.
Even a little absorbed water starts reactions that degrade the fuel. Aviation fuels contain no alcohol and they likely never will. Too dangerous to rely on fuels that turn to sh-t. The EPA has mandated that oxygenated fuels be used in most areas to mitigate certain smog forming emissions, this generally requires that up to 10% ethanol is added to all auto gasolines since MTBE has been banned in most states. This means that the fuel must be fresh or it is near worthless. I have stored 100LL alkylate aviation fuel for years and it is as sweet as ever with no degradation. Can't run it in anything with a cat because it contains lead, but my vintage offroad motorcycles loved it.
I don't know how old you are, but back in the day, (50's and 60's, even into the 70's), motor fuels could be stored in tight cans forever and they would still be good. Modern gas with alcohol goes bad in a few months even when sealed up, especially if ambient temps are high. The old gas could be evaporated down leaving only small residues. Try putting a cup of new fuel out to evaporate and see what you end up with: nasty corrosive goo. The oxygenation of gas causes self decomposition and also reduces the calorific value of the fuel. Fuels that contain less energy per volume give poorer MPG results. Fuels that are oxygenated with alcohol are crap.
Interesting. Leaded fuel is a little bit before my time. My Father says back when they were switching-over, would on rare occasion, see someone with a newer vehicle use a funnel to fill up their vehicle with leaded fuel over the fact that it was a nickel cheaper. Says he realized those must've been rentals, as couldn't imagine someone ruining an engine to save 25 cents on a fillup.

No idea what is/was going on with BP fuel but years ago had learned to avoid them. Not only did I hate the smell of it, but would get way way less power. Supposedly all brands are the same; just different additive packages. Guess it was something about their package.

Thanks for the info/correction MB.

Millball, what color is the 100LL gasoline in your area?

I frequently get decent gasoline from an acquaintance in the hazmat business, and recently I got a jerry can of beautiful blue, toluene smelling fuel. Researching gasoline in my area of western Canada shows that this colour is only used for 100LL. I suppose it could also be ordinary gas with two stroke oil mixed in, even though I haven't seen blue two stroke oil.

I don't want to run this in the Escort if it is leaded due to the oxygen sensor and catalytic convertor.

I haven't found a simple way to test for lead in fuel. Anyone know of any?
The 100LL available to me is indeed a beautiful blue color. I don't know of any other fuel that is blue dyed.
I would never consider running any fuel of unknown character in any machine with a catylitic converter.
The risk of damage to the converter is too great.
If your blue fuel is clean, I would'nt be afraid to use it in non cat applications.
As a point of interest, the low lead designation of this av-gas only refers to it having less lead content than earlier aviation fuels did. This 100LL fuel still contains as much or more lead than any leaded automotive fuels ever did.

I don't know of any quick test for lead in fuels, but maybe someone out there can tell us.

"I would never consider running any fuel of unknown character in any machine with a catylitic converter. "

Too late- I've run a ton of this scrounged fuel (not the blue fuel) in the car and others in the fleet. We haven't had leaded fuel here for about fifteen years so other than the blue gas, the chances of having usable leaded gas that is fifteen years old seems remote.

I scan the codes regularly and the emissions still is "green" on the Innova code reader.

I have learnt a lot about fuel systems in the time I've been doing this. It can be a hassle but I'm prepared for trouble- I always carry a spare fuel pump, filter etc. in the vehicle. If I ruin the convertor, I'll get a junkyard one and still be way ahead money wise.
I have to ask if these pictures are available anywhere? It's an old thread, for sure, but super critical to see the pics. Any ideas?
I know this is a old thread but i hop these guys are still here.Nice work on this but i can't see any pics.
I know this is a old thread but i hop these guys are still here.Nice work on this but i can't see any pics.
Most of the members in the beginning of this thread have not been on in years.
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