1984 fuel pump no pressure.

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DavidMWilmes

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Hey guys, I have a 1984 351ho Broncos.

I have replaced everything on the electrical side. Besides wiring. (Alternator, starter, solenoid, distributor, plugs, coil) I just replaced the mechanical fuel pump because the carb isn't getting fuel. Yet, I'm still not getting fuel, I can **** gas out from the line by the carb. But it doesn't seem like pump is pushing gas to th3 carb. Not sure what to check since its brand new.

 

miesk5

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Yo Irished,

Welcome!

Is fuel filter clean?

If it's a mechanical pump, the pump arm may not be in resting on on cam lobe. See attached depiction, the arm is to the upper right of tbe pump body.

"Take a look at the fuel lines from the tank to the carb, looking for any holes or collapsed spots..."

by our late friend Randy (Justshootme84).

"Take a good look at the fuel line. Places where it has a bend in the line and is close to the manifold is prime for contacting heat and causing problems. Look under the vehicle, I have seen a hole in the exhaust pipe blowing on the fuel line, and causing the problems you describe. " by Rons Beast

Mechanical Fuel Pump Installation in an 84 Bronco:

"Disconnect the fuel inlet and outlet lines at the fuel pump. Discard the fuel inlet retaining clamp.

Remove the pump retaining bolts then remove the pump assembly and gasket from the engine. Discard the gasket.

If a new pump is to be installed, remove the fuel line connector fitting from the old pump and install it in the new pump.

Remove all gasket material from the mounting pad and pump ******. Apply oil resistant sealer to both sides of a new gasket.

Position the new gasket on the pump ****** and hold the pump in position against the mounting pad. make sure that the rocker arm is riding on the camshaft eccentric.

Press the pump tight against the pad, install the retaining bolts and alternately torque them to 20-24 ft.lb. on the 8-302; 14-20 on the 8-351; 19-27 ft.lb. on the 8-460. Connect the fuel lines. Use a new clamp on the fuel inlet lines.

Operate the engine and check for leaks." by Chilton

...

Pressure Check:

"Remove the air cleaner assembly. Disconnect the fuel inlet line of the fuel filter at the carburetor. Use care to prevent fire, due to fuel spillage. Place an absorbent cloth under the connection before removing the line to catch any fuel that might flow out of the line.

Connect a pressure gauge, a restrictor and a flexible hose between the fuel filter and the carburetor.

Position the flexible hose and the restrictor so that the fuel can be discharged into a suitable, graduated container.

Before taking a pressure reading, operate the engine at the specified idle rpm and vent the system into the container by opening the hose restrictor momentarily.

Close the hose restrictor, allow the pressure to stabilize and note the reading. The pressure should be 5 psi.

If the pump pressure is not within 4-6 psi and the fuel lines and filter are in satisfactory condition, the pump is defective and should be replaced.

If the pump pressure is within the proper range, perform the test for fuel volume." by Chilton

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DavidMWilmes

DavidMWilmes

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It actually doesn't have a fuel filter on it atm. For some reason it's just a rubber hose where it should be. But either way. So I know the lines arnt clogged. I can **** the gas thro the carb hose myself, just no pressure when cranking. I know that without a pressure test. As I'm getting no fuel once so ever. Unless I **** on the hose.. like I said. I just replaced the fuel pump.

It went in without a problem. Had to push it some. How do I know where the eccentric is? Or is that to just ease installation?

 

miesk5

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miesk5

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Yo,

I was hoping that other members would offer advice.

The lack of the fuel filter bothers me.

Could be  rust in tank blocking flow.

How long have you owned your 84?

 
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DavidMWilmes

DavidMWilmes

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I've put one in. Since. A clear one, it's getting fuel thro it. It's a possibility.

I've had it a month. I bought it for 300 dollars. It's been sitting for 3-4 years on the coast of Oregon. So it's rusted out in a lot of places.

Like I said. I'm able to **** fuel thro the lines where it comes off at the carb should I be able to do that? After not trying to turn it over for a few days. It squirted a tiny bit a fuel then stop and wouldn't do it again.

I'm so lost. I'd assume that by sucking fuel out from the carb. That I don't have a blockage somewhere. Am I wrong with the assumption?

And like I said I just replaced with a new pump and reinstalled twice now. I'm going to take it off and see if I can't get a picture of the inside of the engine to see if it's aligning right.

Also it has a bigger cam in it supposedly does that change anything?

 
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miesk5

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Yo,

Try removing the gas cap and seen if it runs.

How does the gas line look at the tank?

Try removing the line to see how much fuel flows out. Be prepared to catch the fuel in a plastic container.

Tge cam should have the eccentric up front.

One of the you tube videos shows it.

Unfortunately, Seabronc hasn't been on line here, he would know more.

 

johnnyreb

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I've put one in. Since. A clear one, it's getting fuel thro it. It's a possibility.

I've had it a month. I bought it for 300 dollars. It's been sitting for 3-4 years on the coast of Oregon. So it's rusted out in a lot of places.

Like I said. I'm able to **** fuel thro the lines where it comes off at the carb should I be able to do that? After not trying to turn it over for a few days. It squirted a tiny bit a fuel then stop and wouldn't do it again.

I'm so lost. I'd assume that by sucking fuel out from the carb. That I don't have a blockage somewhere. Am I wrong with the assumption?

And like I said I just replaced with a new pump and reinstalled twice now. I'm going to take it off and see if I can't get a picture of the inside of the engine to see if it's aligning right.

Also it has a bigger cam in it supposedly does that change anythii
 

johnnyreb

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What brand of fuel pump is it? I went through 5 AIR TEX before I went to CARTER and haven,t had any problem since. The last AIR TEX started my bronco (78) 1 time and would after that. This ethanol will mess one up quicker the anything. Pour some in a clear bottle and set it aside. 2 weeks look at it. It looks like syrup. It ruined a new carbeurator on my Bronco. I went to 100% pure gas and don,t have anymore problems getting my parts ruined anymore. Also you might want to replace all the rubber hose and see how it does. Brake hoses collapse on the inside. The ethanol gas is also ******* rubber and plastic.
 

johnnyreb

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What brand of fuel pump is it? I went through 5 AIR TEX before I went to CARTER and haven,t had any problem since. The last AIR TEX started my bronco (78) 1 time and would after that. This ethanol will mess one up quicker the anything. Pour some in a clear bottle and set it aside. 2 weeks look at it. It looks like syrup. It ruined a new carbeurator on my Bronco. I went to 100% pure gas and don,t have anymore problems getting my parts ruined anymore. Also you might want to replace all the rubber hose and see how it does. Brake hoses collapse on the inside. The ethanol gas is also ******* rubber and plastic.
The air tex WOULD NOT start after that 1 time.
 

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