ran when parked, fuel pump not pumping

[tow hook]

(  i have a 62 3b with a duel diaphragm fuel pump )   

   last Nov. the top diaphragm gasket was leaking gas on to the fender. i tightened up those bolts and removed the pump to reseal the fuel pump at the engine block. it ran fine after wards. now 6 months later no fuel  in the sight glass after cranking the starter. any ideas i can try before i take it apart ? it will run with fuel poured into the carburetor.

[Rus Curtis]

Check the dipstick to see if the oil looks thinner or has a gas smell.

A typical problem when a diaphragm on these mechanical pumps fails is for the gas to be pumped into the oil pan.

If so, you'll need a new diaphragm and an oil change.

[scoutpilot]

Pictures of the pump and fuel supply lines in the engine bay would help.

[tow hook]

Check the dipstick to see if the oil looks thinner or has a gas smell.

A typical problem when a diaphragm on these mechanical pumps fails is for the gas to be pumped into the oil pan.

If so, you'll need a new diaphragm and an oil change.

thanks i will check that now. there is a hint of a gas smell on the oil. i'd say it's from me pouring gas in to the carb. vs the pump..... the new fuel filter i installed is still dry

[tow hook]

Pictures of the pump and fuel supply lines in the engine bay would help.

 let me see what i can do.    thanks rick for the gasket for the sight glass that you sent me last fall. even though i just had to tighten up the the screws at the top to keep the gas leaking from the diaphragm.... are you still avl for rebuilds ?  i try and run my tank empty, and run non ethinall gas before storage. for easier start up

[scoutpilot]

Looking forward to the photos. I am, but patience is required. Five weeks minimum lead time.

[tow hook]

Looking forward to the photos. I am, but patience is required. Five weeks minimum lead time.

ok, thanks heres the pics

<img src="https://www.mywillyspics.com/images/2026/03/25/KIMG2420.jpg" alt="KIMG2420" border="0">
<img src="https://www.mywillyspics.com/images/2026/03/25/KIMG2421.jpg" alt="KIMG2421" border="0">
<img src="https://www.mywillyspics.com/images/2026/03/25/KIMG2422.jpg" alt="KIMG2422" border="0">
<img src="https://www.mywillyspics.com/images/2026/03/25/KIMG2423.jpg" alt="KIMG2423" border="0">

[scoutpilot]

Oil smells of gas—no gas in the glass filter. Unless you've dumped a pint of gas down the carb's throat in short order, I would suspect a bad fuel diaphragm. It sat for six months? I know you wrote that you run the carb to dry. You run it until the tank is empty? If so, that's a good way to let trash in the tank collect in the plastic filter, and get to the pump and mess with the valves.  When was the last time you changed out the plastic filter?
As an aside, the worm-gear clamps are not good for rubber to straight-cut steel. After six months, dried out, those connections may be leaking air into the system. I recommend fuel injection clamps.
And yes, if you've verified gas in the oil, change the oil and filter immediately. Consider rebuilding the pump, also.

[tow hook]

Oil smells of gas—no gas in the glass filter. Unless you've dumped a pint of gas down the carb's throat in short order, I would suspect a bad fuel diaphragm. It sat for six months? I know you wrote that you run the carb to dry. You run it until the tank is empty? If so, that's a good way to let trash in the tank collect in the plastic filter, and get to the pump and mess with the valves.  When was the last time you changed out the plastic filter?
As an aside, the worm-gear clamps are not good for rubber to straight-cut steel. After six months, dried out, those connections may be leaking air into the system. I recommend fuel injection clamps.
And yes, if you've verified gas in the oil, change the oil and filter immediately. Consider rebuilding the pump, also.

i did over dump gas into the carb   it sat November  threw march. ok i didn't know that. ( my tank is new and very clean ) i changed the paper filter every year. in the spring as a part of maintenance. ok i will change the clamps . ok great. i thought i was doing ok.


 what s the best way to store the 3b non ethinal gas a and some stabilizer ?

 thanks for the help, i thought i knew better

[scoutpilot]

Do you know how many mistakes I made years ago? I still make mistakes. Fortunately, like you, I learned to ask questions and read Jeep books. There's no such thing as a dumb question!

Storage protocol depends on the conditions the vehicle will be in while in storage.

[tow hook]

Do you know how many mistakes I made years ago? I still make mistakes. Fortunately, like you, I learned to ask questions and read Jeep books. There's no such thing as a dumb question!

Storage protocol depends on the conditions the vehicle will be in while in storage.

 ok, so i plan to have my 3b off the road from nov. threw april . it's a in a dry cool / cold garage or my storage unit. any  thoughts for storage prep?

 thanks

[scoutpilot]

Best is with zero fuel in it from the tank to the carb. Second best is full of fuel. What humidity levels will it encounter?

[tow hook]

Best is with zero fuel in it from the tank to the carb. Second best is full of fuel. What humidity levels will it encounter?

i'd guess low?    it's in a cool dry place 97% of the time. with a lot of rain the floor could be damp for a day or so

[tow hook]

Check the dipstick to see if the oil looks thinner or has a gas smell.

A typical problem when a diaphragm on these mechanical pumps fails is for the gas to be pumped into the oil pan.

If so, you'll need a new diaphragm and an oil change.

 today i put on a lawn mower tank to test run  the trans that i redid over winter. ( the fuel pump is on it's way to rick ) the carb flooded again and was dumping gas down the pass side of the engine. the choke knob was stuck. i unscrewed it form the base ( of the carb ) the holds the outer sleeve, and the choke screw. the cable is working freely.    the choke pivot was bound up by the clamp bracket the holds the intake horn on to the carb.... i will change the oil now   that oil had 5 mins of idling on it ...


so due to the choke being open the carb flooded ? even with the gravity feed ? or do i have other issues ?

 thanks

[Rus Curtis]

Typically, if the choke is open, there's minimal chance of flooding.  Perhaps running lean.  The choke doesn't restrict or increase the fuel but does restrict the air flow (which is why it's up on the top) to allow for a temporary rich mix to help with starting.  If stuck closed, then there's a remote possibility to flood but more likely a rich rough idle.  As I understand it, there's no effect on fuel flow, just air intake.  There is more likely a possibility to flood if you keep pumping the pedal with your foot as that pumps raw gas into the intake manifold.

Not an expert on the carbs but you may free up the choke with penetrant or starter fluid.  Rick will know better. 

More importantly, are you going to paint the lawnmower tank to match your jeep and use it for a secondary tank on long runs?