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August07

Member
Joined
Jan 3, 2024
Messages
14
Reaction score
8
Location
California
My Car
Gold 1972 Grande, H-type
hey yall, I was driving my mustang out today and it randomly dropped fuel pressure then died and now refuses to start at all. The Float bowl is completely empty of fuel and pressing the accelerator pushes no fuel into the engine. I’m not out of gas because I just filled up this morning. Any thoughts?
 
You could just replace the fuel pump, but it may not be that. If you want to determine what’s wrong, without just replacing stuff until you stumble upon the problem, you’ll need to verify you have fuel at the pump. Remove the wire from the coil to the distributor, remove the fuel line to the fuel pump, and crank it, while putting your finger over the fuel pump inlet. If it’s working, you should feel it sucking on your finger. If you feel nothing, it’s like a bad diaphragm. You can pick up a good pump an NAPA. If you do have good suction, I would remove the fuel line at the tank, and blow compressed air through it to see if it’s clogged. Also, since it’s new to you, look for filters in unusual places, in case it’s clogged up. Good luck.
 
I'd like to suggest rebuilding the entire fuel system. Your car is somewhere between 51 and 53 years old, and I'll bet most of the system is original... and worn out. I recently did this service with my '72 Mustang and my '73 F100. In both cases, I rebuilt the existing (stock) carburetor and replaced everything else except the hardlines on the chassis. New fuel tank, fuel gauge sending unit, vapor vent valve, ALL rubber hoses, all clamps, filler neck seals, fuel pump, fuel filter. Total cost was less than $300. Do it once and never have to worry about any of it again in your lifetime. While you have everything apart, blow out the hard fuel line with compressed air, blowing from front to back.

I bought the tank for the Mustang off eBay:
https://www.ebay.com/itm/295734796177
Nicely made tank with powdercoat finish, fits perfectly, and free shipping! Reputable seller, too.
 
You have gotten some solid advice in the responses prior to me jumping in. I thought I would share the fuel pump test specs for pressure and volume. For you to lose fuel delivery so quickly is an indication you have a fuel pump issue as opposed to a fuel flow blockage issue (filter). Any time I hear about a failing or failed fuel pump I recommend immediately to pull your engine dip stick and see if it has an odor of gasoline. The reason is when a rubber diaphragm inside a fuel pump fails the fuel is often pumped into the crankcase, which will seriously destroy the oil's ability to properly protect your internal parts. In fact, I would do that before performing a fuel pressure pressure ot volume output test, just because it is so critical. Even if you "only think" you smell gasoline, I would not take chances, Engines are very costly to replace or rebuild - especially when it is avoidable.

As for the specs and some photos, I have attached a few files I hope you find useful. The fuel pump performance specs are near the end of the PDF file.

While you are working on the fuel pump (if the fuel pump needs to be replaced) I suggest you change the rubber fuel lines at the fuel tank fuel outlet, at the fuel pump fuel inlet, and at the fuel filter. The filter's fuel line has likely been changed a few times, but the others are normally changed only when they begin to leak. Even my own 50+ year old pony cars came to me with their original fuel lines at the tank and at the fuel pump.

If you have never changed a fuel pump before, it is fairly easy. The trick is to block fuel from pouring over you, coming from the fuel line from the fuel tank. Obviously prevent fuel from getting in any eye, or worse yet inside an ear as it is very painful. In looking at the photos of hoe the fuel pump actuating arm rubs against the camshaft eccentric, you should be able to see how craanking the engine a little at a time so the actuating arm is rubbing on the low spot of the eccentric. That will relieve much of the ac tuating arm spring pressure you will be dealing with when trying to assemble the fuel pump and getting it bolted into place.

I have a few YouTube videos showing how to replace a fuel pump, and fuel lines, on a 73 Mustang with a 302 engine. If you have a 351C the biggest difference is where the mounting holes are located. Other than that it is really the same process. That videos are at:


https://youtu.be/frYaO_u0OZc

https://youtu.be/Xp8vLVlxtVk

https://youtu.be/BmQpNEHPgaw

https://youtu.be/lkKVcliOd2w


If the fuel pump tests good please let me/us know so I/we cqan begin to suggest other approqaches. Likewise, if the fuel pump tests bad, and you get it installed and the engine running (with oil and filter change), please let us know that also.

Ciao!

Gil
 

Attachments

  • _351C_TimingChainGears_FuelPumpActuatingLeverAndEccentric_Photo_01_20220713.jpg
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  • _351C_TimingChainGears_FuelPumpActuatingLeverAndEccentric_Photo_02_20220713.jpg
    _351C_TimingChainGears_FuelPumpActuatingLeverAndEccentric_Photo_02_20220713.jpg
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  • _351C_TimingChainGears_FuelPumpActuatingLeverAndEccentric_Photo_02_Annotated_20220713.jpg
    _351C_TimingChainGears_FuelPumpActuatingLeverAndEccentric_Photo_02_Annotated_20220713.jpg
    1.4 MB · Views: 0
  • FuelPump_VolumeOutputSpecifications_20210502.pdf
    533 KB · Views: 0
Last edited:
hey yall, I was driving my mustang out today and it randomly dropped fuel pressure then died and now refuses to start at all. The Float bowl is completely empty of fuel and pressing the accelerator pushes no fuel into the engine. I’m not out of gas because I just filled up this morning. Any thoughts?
Vapor lock
 
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