Gas not getting to carb?

[alligatorfoot]

Hi,
Before jumping the gun and replacing the fuel pump and looking for a block in the gas tank this upcoming weekend I figured I would reach out to see if anyone had insight about the inability to get gas into my carb. Here is the background:
My petrol (NOT diesel) truck ran out of gas, got AAA to add in about half a gallon in to get me home and for the last two months I have had the car in the garage while doing a variety of cosmetic work (did not start it). Long story short is that I went to start it up, cranks but won't kick over. I put in quick start into the carb (multiple times) and it kicks over starts and then dies back out. It is clearly a fuel delivery issue. Added another 2 gallons into the tank, still nothing. Although unlikely to really help I took the gas cap off to help the gas flow easier and still nothing. Rocked the car in the event that debris was covering the line exiting the gas tank, still nothing. Not sure what to do next given that I have not done anything mechanically to the car since it last started? Can a fuel pump go bad sitting there (also I have a clear fuel filter and it looks dry). Any ideas that anyone has would be greatly appreciated.

Best Regards,
Mark

[stomper]

Your fuel pump, if original should have a glass sediment bowl attached to it. you need to clean it out, as it is likely plugged with crap from running the tank dry. take a moment while you are there to blow some compressed air down the fuel lines. If that doesn't work, just undo the pick up tube from the fuel tank, and check to see if it is clogged.

[I Leak Oil]

...and if you have an original style pump it will have a primer lever. What does it do when you pump it? Does fuel flow to the filter? If you disconnect the line at the carb and prime it does fuel come out?

[alligatorfoot]

Thanks for the insight. l have the metal one. Is it possible to take this one out and apart and clean it out? I tried to gently tap at it to possibly jar lose any sediment but didn't try too hard for fear of busting it.

[stomper]

No way to clean it, but it can be rebuilt. Check the pick up in the tank, there are just 2 screws holding it in. Blow out the lines from the pump back to the tank, or if they are old, replace them with rubber line from the Autopart store. Prime the hand lever to see if you can draw fuel up to the pump, and then see if you can draw it through the line to the carb. All this should only take you about 30-45 minutes. Then you will know a lot more about your problem.

[disco2hse]

Long story short is that I went to start it up, cranks but won't kick over. I put in quick start into the carb (multiple times) and it kicks over starts and then dies back out. It is clearly a fuel delivery issue. Added another 2 gallons into the tank, still nothing.

It is not clear that this is a fuel supply problem. Your description indicates a lack of spark (electrical). With ether or engine start, a weak spark will turn it over until the highly volatile fuel is burned off, then it will die.

You should check your plugs for indications of condensation/oil and work backwards from there, through the leads, distributor cap and points, condenser, coil, earths and even the battery itself (check that the battery has 12.4V available).

[o2batsea]

I don't know where you get that Alan. It does start and run on ether so it's not electrical. The other thing one might check is the needle valve in the carb. It can get gummed in place especially after sitting for a long while with no gas. Float drops as the gas in the bowl evaporates, leaving the needle valve stuck closed.
No amount of priming or even replacing the fuel pump will cure that. So, you gotta check the bowl which means pulling the top off the carb and cleaning the valve and seat. Might as well check the float setting as long as you're in there. Oh and clear out any crud in the bottom of the bowl.
To check the fuel pump take the inlet hose off the carb and point it into a glass jar. Go crank the engine about ten revs. Go check the amount of fuel in the jar. If it looks like a healthy dose, the pump is good. Your problem is the carb. If not, then the trouble is between the pump and the tank.

[bugeye88]

Yep, it could be a needle valve. You didn't mention what carb you have, but they are all vulnerable to this, some more than others. Weber 34 ICT carbs are especially prone to this as the valve is at the bottom of the float bowel. An inline fuel filter before the carb will help prevent this. As batsea said, it's a good idea to check this first, then all the other suggestions on fuel lines and pumps. I run a electric pump after the mechanical one that has an on and off switch in the cab to prime the carb for quick starts (saves the starter) and can serve if the mechanical one fails.

KTF
Rob

[stomper]

I disagree with cracking open the carb first, but I guess it is just semantics and personal preference. I prefer to rule out the simple things first, and cracking open the carb, while not challenging, does require a little more time and precision. Plus, you will likely need a new gasket to seal the carb if it hasn't been opened in a while, as the gasket gets brittle and typically cracks upon separating the carb.

Additionally, if the clear inline filter appears dry, like the OP states, then it isn't likely to be a carb issue. His symptoms started after running out of fuel, which would suggest debris, not a stuck needle valve. Diagnosing any problem is difficult over the internet, especially without additional information. Until some additional info is provided, we can all punt around suggestions, but it may just confuse the OP in his areas to check and diagnose the issue.

[bugeye88]

Yeah, sure.... It could be any or some combination of the things suggested in this thread. I think everyone is trying to help out with things that have helped them in similar situations with Landy's or other vintage cars. All good.

[disco2hse]

I don't know where you get that Alan. It does start and run on ether so it's not electrical. The other thing one might check is the needle valve in the carb. It can get gummed in place especially after sitting for a long while with no gas. Float drops as the gas in the bowl evaporates, leaving the needle valve stuck closed.

A weak spark will allow a vehicle to run with an increased octane (ether does that), but it will flood easily too, hence wet plugs. In fact, it might be as simple as burned or fouled plugs.

But I agree that the carb might also be an issue and that it may be an air leak. A quick check is to look down the throttle and see if fuel is squirting in. I am not so certain about an air leak. That tends to show different symptoms.

[I Leak Oil]

TAKE THE LINE OFF THE CARB AND MAKE SURE YOU'RE NOT GETTING FUEL UP THERE. WORK YOUR WAY BACK.....SORRY FOR SHOUTING BUT MY GOD, THIS ISN'T ROCKET SCIENCE!

....there....I feel better now.

[stomper]

Lol, I think I just pissed myself laughing Jason! Keep calm and have a beer! See you this weekend for a cold one!

[I Leak Oil]

Lol, I think I just pissed myself laughing Jason! Keep calm and have a beer! See you this weekend for a cold one!


You mean next weekend right??? Or am I slow on the uptake somewhere again?

[SafeAirOne]

Disregard this post--Changed my mind and tried to delete it it as best I could...

[stomper]

Yeah, I'm getting ahead of myself. I just want this week to be over!

[Contractor]

TAKE THE LINE OFF THE CARB AND MAKE SURE YOU'RE NOT GETTING FUEL UP THERE. WORK YOUR WAY BACK.....SORRY FOR SHOUTING BUT MY GOD, THIS ISN'T ROCKET SCIENCE!

....there....I feel better now.


lol

I had the same thing typed yesterday and decided to hit delete.

[I Leak Oil]

Good or bad I seem to forget where my delete key is these days. Nothing personal.

[ivan]

THANKS

[pyounts]

Having same issue as original post. Ran it out of gas and found their was no fuel to carb. Took line off going to fuel pump and gas gets to fuel pump. Cleaned bowl and then took top off of fuel pump. Really looks pretty clean and I didn't find any trash. Everything in fuel pump looks ok. Put it back together and still nothing. Did priming lever a bunch but it is not sucking anything into the sediment bowl.

Any ideas?

[Contractor]

Having same issue as original post. Ran it out of gas and found their was no fuel to carb. Took line off going to fuel pump and gas gets to fuel pump. Cleaned bowl and then took top off of fuel pump. Really looks pretty clean and I didn't find any trash. Everything in fuel pump looks ok. Put it back together and still nothing. Did priming lever a bunch but it is not sucking anything into the sediment bowl.

Any ideas?


If you have no fuel to the carb you can work backwards to a fuel filter (assuming you have one). If it's clean and still no fuel to the carb, continue to work backwards to the fuel pump. Clean the glass bowl and re-seat in the rubber gasket..........if it does not seat perfect you are going to get an air leak and it's not going to prime. While it's a pain in the ass the best way to ensure a tight seal is to pull the pump off the block and re-seat the bowl on the workbench, then re-install the pump.

The little hand prime sucks.......keep turning the motor over with the key to get it to prime.

If you still get nothing you can go backwards yet again and check the fuel pickup tube and screen. If your tank is full of rust, dirt or water drain it.....clean it.....change the filter and try again.

There are only a few things that are going to screw you up between the tank and the carb:

- Pickup tube/Filter
- Fuel Pump
- Paper inline filter

Process of elimination, around six beers, philips head screw driver and 1/2" open ended wrench should cure what ails you.

[pyounts]

Thanks! I've really done all of that. Gas gets to the fuel pump but does not come out. Do you have to prime it with gas to get it to start pumping?

I saw something in an earlier post about using a syringe.

[I Leak Oil]

Perhaps the diaphram has a leak or the out check valve is stuck closed.

[pyounts]

I read on another post (maybe a joke) to try and suck gas into the fuel pump. We'll I tried but from the output end and it is closed or stopped up.

[ArlowCT]

Any chance the one way check valves got flipped when you had the pump apart. There should be two in it, one in each side of the diaphragm.

[pyounts]

I took the top off of the fuel pump, but didn't see any loose parts that could have been put back in wrong.

[I Leak Oil]

If you put a fresh hose on the intake port and run that into a jar a fuel will it pump then? If not it's your pump. If so, keep looking at the lines, pickup tube and tank.

[SafeAirOne]

3 pages/24 posts...well, 25 now...and we still haven't identified the exact point at which the fuel stops flowing in a system that consists of a grand total of 4-components (one of which is "fuel hose")? :confused:


Good thing it's not ignition-related!

[I Leak Oil]

3 pages/24 posts...well, 25 now...and we still haven't identified the exact point at which the fuel stops flowing in a system that consists of a grand total of 4-components (one of which is "fuel hose")? :confused:


Good thing it's not ignition-related!

Hey, I'm supposed to be the bad cop in the good cop\bad cop routine!

[SafeAirOne]

Hey, I'm supposed to be the bad cop in the good cop\bad cop routine!

Oops...Sorry Jason--Bit of a misunderstanding, I'm afraid. Let me go behind you where I will struggle to restrain you while you attempt to break free of my bonds and go berzerk. ;)

[I Leak Oil]

Good thing you're bigger than me (I mean that in a good way) so you can hold me back. Otherwise I'd be forced to flog someone with a clogged fuel hose! With my luck this week though, I'd miss and hit myself instead....