First startup unsuccessful. Bad fuel sending unit?

[Guest TheDude]

I tried to start the Buick for the first time since 1992 but I was unsuccessful. There is no fuel getting to the fuel pump. I have a clear fuel filter before the pump and I can see that there is no fuel. It must be the fuel sending unit. Maybe there is a clog or it is just broken. Can it be anything else? Is there such a thing as air in the fuel lines (as in when you bleed the brakes)? Does it have to do with a vacuum source?

The engine turned (put some starting fluid in the carburetor) and the electrical system seems to be fine. The lights and horn work (I found out about the horn when I was under the hood and my friend accidentally pushed the horn ring).

Thanks,

Justin

[imported_buick5563]

Hey Dude,

Is the gas fresh? Really fresh? Did you drain all of the old gas? There isn't a fuel sender on your car, the fuel pump sucks it. It is possible that there is air in the lines, but that should go away when you start the car, thereby pulling fuel from your tank through the fuel pump to the carb. Make sure that gas is fresh, and never stick your face over the carb when you're messing with it if you value your eyebrows.

If you try this and it doesn't work, you may need to try electrical diagnosis. Your lights and horn aren't part of the starting system. Have you already changed out: coil, distributor cap, points, rotor, plugs, etc.

Mike

[Guest TheDude]

Thanks Mike,

The gas just came from the gas station today. The fuel tank and lines are cleaned out and the coil, plugs, wires, rotor, cap, and points are new. I rebuilt the carburetor and had the fuel pump rebuilt by a reputable shop. I poured all of the gas into the tank and forgot to save some to put in the carburetor. Should I try that and see if it gets things going?

[imported_buick5563]

Justin,

I just woke up and immediately realized that I misinterpreted your "sender" remark. I thought you meant a mechanical sender. The in tank gas guage has a tube attached that is also called a sender (Duh, my bad). That tube could be clogged from sitting in a mucky tank. If it is you will need to pull the tank to access it. Sorry for the misunderstanding <img src="http://forums.aaca.org/images/graemlins/blush.gif" alt="" />.

Good luck,

Mike

[Guest TheDude]

I got under the tank and slightly loosened the nut where the sender meets the fuel line and some dark brown liquid seeped out which makes me think its clogged as well. I have the tank out so I'll look at the sender. Thanks!

[Guest TheDude]

I can blow compressed air through both ends of the sending unit and the air comes out both ends with good force. Can I now suspect that there is some kind of vacuum source that is not functioning? Where is the best place to look?

I attached a drawing of the fuel system setup.

[imported_buick5563]

Justin,

I don't know about your car specifically, but if you have a dual diaphragm on your fuel pump, the vacuum half ONLY goes to your wiper. I don't think there is a vacuum problem you could be having in regards to the fuel delivery. Does it start if you put gas in the carb?

Mike

[old-tank]

How much gas is in the tank? If you don't have at least 5 gallons the fuel pump will take a long time to pump fuel if the line is dry.

Another thing to try is to blow air into the gas tank filler, sealing with a rag. If now go, disconnect the line before the fuel pump and gas should come out...work your way to the carb. Look for leaks in all lines especially the suction portion (tank to pump) which would cause the pump to pull air rather than fuel.

Willie

[Guest TheDude]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> Does it start if you put gas in the carb? </div></div>

I poured all of the gas in the tank and forgot to save some for the carburetor. I will have to get some gas tomorrow or Tuesday and see what happens. If it starts with gas in the carburetor could that help get the fuel flowing?

[Guest TheDude]

I poured about five gallons in the tank. We pumped the accelerator pedal a lot. I checked for leaks and found nothing. It all looks fine. Could the filter I have before the fuel pump be causing any problems?

[Guest ZondaC12]

i didnt have this problem with the '38, it had 25 year old fuel in the lines all the way to the pump at least <img src="http://forums.aaca.org/images/graemlins/blush.gif" alt="" /> so it shot right up there. but the 79 spitfire we also have i tried to start last year and the lines were dry. just wouldnt suck it in!!! so, i detached the line from the carb, and carefully dumped gas in with a catch can underneath, so when it overflowed it didnt get all over the garage floor! started right up and ran great!

i think these mechanical pumps are useless for sucking air. just doesnt happen. gotta prime it! try that and see what happens.

good luck, cant wait til she comes to life for ya!

[Pete O]

Just grasping at straws here. Are the in-line fuel filters installed tightly, so that there is no air leakage? Are there any rubber lines that might be cracked or pourous? The suction from the fuel pump could be escaping through any loose fittings.

[BamaWildcat]

One more thing: Old rubber hoses may be collapsing under the pressure of suction stopping the flow.

[Guest TheDude]

The rubber hoses are new as well as the fuel filters and the hoses are tightly secured. I'll try priming the carburetor sometime this week (just worked 13 hours today <img src="http://forums.aaca.org/images/graemlins/crazy.gif" alt="" />) and see how that helps. Everything looks fine as far as I can tell. I don't have any experience with starting a car that has sat for this long so I'm learning a lot. <img src="http://forums.aaca.org/images/graemlins/smile.gif" alt="" />

[bhclark]

I got my '40 started today for the first time since I bought it.

My secret to success was:

-Plenty of power (00 gauge battery cables to make sure I was getting full use of the 6 volts)

-brand spanking new spark plugs. (old ones weren't worn but they were wet and carbon fouled)

-I filled a spray bottle with gasoline and lightly misted the carb while pulling on the starter.

After a few tries, i was able to keep her idling by slowly misting the carb with the gas. (watch those eyebrows!!!!)

This won't tell you if you have a fuel pump issue, but it might help get her started.

Other than that, time could be off significantly or the coil could be bad based on waht you've already done.