No fuel to carburetor

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bigfoot72

Well-known member
Joined
Oct 8, 2014
Messages
66
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Location
Seattle, WA
My Car
1972 Ford Mustang Coupe
I own a 1972 Mustang and over the last 2 years did various fixes and modifications. These included getting the heads refurbished to fix a hairline crack, adding an Edelbrock Performance Intake Manifold, Edelbrock Thunder Series 650cfm carburetor with electric choke, and a new Precision mechanical fuel pump. I am starting the car for the first time in 2 years now and the car cranks strong but no fuel is entering the carburetor, or even the fuel line going from the pump to the filter. When I replaced the old pump today and disconnected the rubber fuel line going to the tank some fuel came out of the hose but not a lot. I’m honestly stumped on why the car isn’t starting. It has about 5 gallons of new fuel in the tank, all of the vacuums are hooked up or blocked to the best of my knowledge. The only thing that isn’t attached is the positive wire of the electric choke as I am still not sure where to hook that up to. Any ideas on what could be preventing my car from starting? I’d appreciate any help!

 
It could be a bad fuel pump! Do you have any starter fluid? I would start there to see if you get it running enough to pressurize the fuel system. The starter fluid would also help to make sure the engine is firing.

 
Do you use non-ethanol fuel? If you have fuel with ethanol and you leave it sitting for a while it can go bad and clog something. They make a stabilizer for it for people who have equipment sitting during the winter or something.

If it's an old tank you might have a clogged sock from corrosion too. So for me that'd be where I'd look if you've taken the hose off at the tank and you didn't get much fuel flow.

 
Pour a little gas in the bowl vents of the carb until it'll shoot gas out the accelerator pump nozzles. It should run enough to pull fuel from the tank and fill the carb. You might need to do it a couple times. If not, take the inlet hose off the pump and run one from a small can of gas to the pump. That'll tell you if the pump is good or not.

 
The fuel lines can get plugged with varnish from sitting with fuel drying out in them, unless they were blown out after it was last run. Old rubber fuel hoses can collapse internally plugging them. Any varnish, rust, or other gunk will quickly plug the inlet valve in the pump. It just takes a pin hole in the rubber or steel lines, or a slightly loose connection, to allow air into the line, which the pump will pull instead of gasoline.

 
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My starting drill for an engine that has been sitting is to fill the carb through the vent tubes, and have a rag soaked in clean gas (and mostly rung out) in hand over the carb. By squeezing it, you can get some fuel to keep it running for a few seconds even after the bowls run dry. If it isn't pumping gas by then use an external tank to test the pump. If pump is bad replace, if pump is good, blow out the fuel line and if fuel doesn't start flowing, you'll need to drain the tank and inspect the sending unit/pick up and lines.

Ethanol is nasty stuff. Carb may need a good cleaning

 
if u feel the line might be plugged... remove the line from fuel pump.. REMOVE gas cap and use compressor to blow into tank.. u will hear it.. please make sure u remove the cap for if u don't u just might get sprayed with gas. then rehook and drop some gas down the carb and start it.

 
It could be a bad fuel pump! Do you have any starter fluid? I would start there to see if you get it running enough to pressurize the fuel system. The starter fluid would also help to make sure the engine is firing.
Yeah i thought it was a bad fuel pump and so i replaced it yesterday with just another mechanical fuel pump from O'Reillys. I used starter fluid before when the old fuel pump was in and the car wanted to start and then would seemingly blow some of the starter fluid out of the carburetor..

 
Do you use non-ethanol fuel? If you have fuel with ethanol and you leave it sitting for a while it can go bad and clog something. They make a stabilizer for it for people who have equipment sitting during the winter or something.

If it's an old tank you might have a clogged sock from corrosion too. So for me that'd be where I'd look if you've taken the hose off at the tank and you didn't get much fuel flow.
I just used 87 octane pump gas from Safeway fuel.

 
The fuel lines can get plugged with varnish from sitting with fuel drying out in them, unless they were blown out after it was last run. Old rubber fuel hoses can collapse internally plugging them. Any varnish, rust, or other gunk will quickly plug the inlet valve in the pump. It just takes a pin hole in the rubber or steel lines, or a slightly loose connection, to allow air into the line, which the pump will pull instead of gasoline.
The steel line running from the pump to the carb looks good with no holes. The hose running to the tank i'm not sure yet because i haven't traced it all the way back to the tank yet.

 
The fuel lines can get plugged with varnish from sitting with fuel drying out in them, unless they were blown out after it was last run. Old rubber fuel hoses can collapse internally plugging them. Any varnish, rust, or other gunk will quickly plug the inlet valve in the pump. It just takes a pin hole in the rubber or steel lines, or a slightly loose connection, to allow air into the line, which the pump will pull instead of gasoline.
The steel line running from the pump to the carb appears to be in good condition with no holes. The hose running from the pump to the tank i'm not sure yet because i haven't traced it all the way back yet.

 
Was the pump installed making sure the pump arm was properly situated on the cam lobe? I'm sure you checked that, but worth mentioning.
It definitely should be, id be surprised if i installed it wrong. I had to sort of blindly install that since i couldn't see the cam but there was only one way the fuel pump fit.. I installed it going downward slightly and then slotted it to the proper fitting.

 
if u feel the line might be plugged... remove the line from fuel pump.. REMOVE gas cap and use compressor to blow into tank.. u will hear it.. please make sure u remove the cap for if u don't u just might get sprayed with gas. then rehook and drop some gas down the carb and start it.
Should i spray the compressed air in the gas tank or in the hose by the fuel pump?

 
Spray into the hose by fuel pump heading back to the tank. Again make sure the gas cap is off so the air has some place to go.

Also you mentioned in an earlier post that you tried starting fluid and it tried to start and sprayed back up. Has the timing been messed with since the last time it ran?

 
Also, you would be surprised how well fuel flows through a fuel line. I recently replaced mine because I found this section under the car during a routine inspection. It was almost flat and the car was running just fine.



 
Also, you would be surprised how well fuel flows through a fuel line. I recently replaced mine because I found this section under the car during a routine inspection. It was almost flat and the car was running just fine.



All the hoses look good and the steel line running from the tank to the pump looks good as well.. 
 
Spray into the hose by fuel pump heading back to the tank. Again make sure the gas cap is off so the air has some place to go.

Also you mentioned in an earlier post that you tried starting fluid and it tried to start and sprayed back up. Has the timing been messed with since the last time it ran?
Yeah so i just tried it again with a little starter fluid being put into the front barrels of the carburetor. When i cranked the engine i'd hear a "Tssst tsst" sound from the carb and some of the starter fluid shoots out the top of the carburetor and i see a little bit of smoke inside the carburetor.

 
I believe Jason asked about timing and if it could have been changed. Sounds like a timing or valve problem. I'm like a couple of others, I always add fuel to the carburetor before I start cranking it. I don't like to grind the starter waiting for the fuel pump to pick up and start supplying fuel to the bowls.

 
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