Fuel only gets to engine when tank is out of the vehicle

[Soundmound]

I mean, you just dragged politics into this for no reason, but you actually made a progressive point right before the dig.

I am an odd duck AG that is for sure, but I was only fooling around. That said, corporations are generally garbage in my opinion. Once an organization reaches a certain size accountability goes out the window. There are just too many moving parts to these massive conglomerates for it. I look at a corporation like I do the general population when it comes to public restrooms. Too many random faces in random places to police them all so most every public restroom is a sopping wet mess of an S show. Giant corporations are the same to me. A virtually unpoliceable sh!tshow and the reason we can't have nice things lol. I did very much appreciate the well structured educational reply though.

 

[Frankenchevy]

“Corporation” is not very descriptive. I have a Corporation. We all have free will.

OP: I’d pull the fuel line to the carburetor, pull the 12v source to the ignition system, safely wrap it up so nothing sparks, put the fuel line into a bucket, crank the engine for a specific amount of time(maybe 6 seconds so the cranking GPM equation is simple), measure the amount of fuel in the bucket and report back.

I’m not real certain what the GPM of a factory mechanical fuel pump is, but someone here will know what is adequate. Then at least you can rule out fuel starvation upstream of the carb. You should have replaced your old soft lines, though. It would be a good time to upgrade to something ethanol resistant. Old lines can collapse, develop leaks, have chunks break off, etc.

 

[AuroraGirl]

“Corporation” is not very descriptive. I have a Corporation. We all have free will.

OP: I’d pull the fuel line to the carburetor, pull the 12v source to the ignition system, safely wrap it up so nothing sparks, put the fuel line into a bucket, crank the engine for a specific amount of time(maybe 6 seconds so the cranking GPM equation is simple), measure the amount of fuel in the bucket and report back.

I’m not real certain what the GPM of a factory mechanical fuel pump is, but someone here will know what is adequate. Then at least you can rule out fuel starvation upstream of the carb. You should have replaced your old soft lines, though. It would be a good time to upgrade to something ethanol resistant. Old lines can collapse, develop leaks, have chunks break off, etc.

corporation as the kind that are buy politicians, offshore jobs, strong arm localities (like amazon), merge and change ownership and take over eachother, most are publicly traded(but not all of course). those

But your corporation is probably employing people for a decent living (I assume it has employees? )
The line replacement is big though, so good call out. The pump is placing those lines under a lot of vacuum, and turned tightly or old hose is liable to kink or collapse.

 

[Challis350]

*I should note that i have very minimal mechanical knowledge. Everything I know about engines i've learnt by watching youtube videos*.

OK mini update. "Worked from home" today but spent 2 hours just fiddling.

First thing to note is that when I pump the gas puddle, no fuel is going into the carb. I just hear air. I don't know how I managed to rev the truck on Sunday night but clearly something has changed since then and now (although the battery is dead - i'm pretty sure the process of pumping the gas peddle and fuel going into the carb is entirely mechanical?)

The tank is back down. I removed the hoses. I actually ran water through them and it came out the other end unobstructed. I dipped the hoses into a small bucket of fresh gasoline and pumped the gas pedal about 30 times, but the fuel level did not change.

I'm going to look at all the filters at the weekend and put new hoses on, but i'm a bit disappointed that i didn't uncover any new information today. Grr.

 

[Frankenchevy]

The only time fuel will move through the carb without the engine running would be the accelerator pump squirting fuel down the carb when you open the butterflies a certain amount. If the carb is dry, no fuel will come out.

The mechanical fuel pump is engine driven. It won’t pump unless the engine is rotating. That’s why I suggested pulling the fuel line from the carb and attempting to pump fuel into a bucket while the engine is cranking over with the starter. Make sure the power is disconnected from the HEI so the engine won’t attempt to fire off.

 

[Challis350]

The only time fuel will move through the carb without the engine running would be the accelerator pump squirting fuel down the carb when you open the butterflies a certain amount. If the carb is dry, no fuel will come out.

The mechanical fuel pump is engine driven. It won’t pump unless the engine is rotating. That’s why I suggested pulling the fuel line from the carb and attempting to pump fuel into a bucket while the engine is cranking over with the starter. Make sure the power is disconnected from the HEI so the engine won’t attempt to fire off.

ah ok i better get the battery charged up - thanks

 

[Frankenchevy]

ah ok i better get the battery charged up - thanks

The fuel line up to the carb should pump fluid into a bucket when you crank the engine. If you don’t get any at first, try cranking for a bit longer, but not too long. You can overheat your starter. Once you get fuel flowing, empty the bucket and crank for six seconds. Multiply the volume by ten. That’s your GPM at whatever the cranking speed is. Assuming your battery is good, I think it’ll crank over at 400ish rpms. That’s about half your hot idle speed in neutral.

Point is, you should have a decent flow of fluid going into the bucket.

 

[Challis350]

Thanks Frank/Jeremy. So i'd remove the section just before the fuel filter right? and I'm guessing if this test fails then the fuel pump is a primary suspect?

All very confusing given i haven't touched any of them.

 

[DoubleDingo]

Frank...lol...Jeremy you got a new name...lol...

 

[AuroraGirl]

*I should note that i have very minimal mechanical knowledge. Everything I know about engines i've learnt by watching youtube videos*.

OK mini update. "Worked from home" today but spent 2 hours just fiddling.

First thing to note is that when I pump the gas puddle, no fuel is going into the carb. I just hear air. I don't know how I managed to rev the truck on Sunday night but clearly something has changed since then and now (although the battery is dead - i'm pretty sure the process of pumping the gas peddle and fuel going into the carb is entirely mechanical?)

The tank is back down. I removed the hoses. I actually ran water through them and it came out the other end unobstructed. I dipped the hoses into a small bucket of fresh gasoline and pumped the gas pedal about 30 times, but the fuel level did not change.

I'm going to look at all the filters at the weekend and put new hoses on, but i'm a bit disappointed that i didn't uncover any new information today. Grr.

what is the SAE number on your hoses and can you share any pictures? I think we asked for pics before, but show us what you are doing

 

[scrap--metal]

So i'd remove the section just before the fuel filter right? and I'm guessing if this test fails then the fuel pump is a primary suspect?

You are correct about where to disconnect the line. It has to be after the fuel pump, which likely means you need to disconnect the fuel line at the carb. The picture below shows the fuel line disconnected from the carb. Once the fuel line is removed, the fuel filter can be checked and/or changed by removing the fitting in the base of the carb that the line was threaded into. A new fuel filter is also shown sitting on the carb in the upper right corner of the picture, but the fuel filter housing is still threaded into the carb.

You must be registered for see images attach

 

[scrap--metal]

Since you dropped the tank again earlier this week, it's possible that you could've already addressed the issue. If the rubber lines were kinked or folded, and limiting your fuel supply, lowering the tank would eliminate that issue. I've replaced several of these gas tanks, and that HAS happened to me once before. I had to drop the tank, reroute/twist the rubber lines into a better position, and re-mount the tank to the frame rails.

If you do check fuel flow with the engine cranking, as Frankenchevy suggested, there should be no question if your mechanical fuel pump is working. Every time the cam lobe hits that pump, these will be a good gush of several ounces of gasoline. It's pretty obvious that fuel is pumping. I'd do this with a helper so you don't have to trust a precariously balanced container to catch the gas under the hood. Someone should hold it while another person hit the key to turn the engine and work the fuel pump, even if the ignition is disconnected.

If that test fails, it's not necessarily the pump that's bad. Clogged pick up on the fuel sending unit, collapsed, cracked, or otherwise leaking fuel lines could also cause no fuel coming from the fuel pump. If the fuel pump pumps appropriately, it was probably a kinked/folded rubber hose, or your fuel filter is clogged up.

I hope this long winded post was educational. I tried to lay things out as clearly as possible because of your self proclaimed lack of experience.

Follow up with additional questions, and good luck!

 

[Challis350]

Hey

I haven't made any further progress since my last post as I'm working and it's dark by the time I get home. I'll be back on it Saturday (with some fresh questions probably!)

But I've kept the tank down as I am going to be comprehensive about this and replace the sender unit and the hoses (but not the fuel lines themselves as that looks like a job too complicated for me). I'll keep the tank down until I actually get fuel flowing. I've also bought a new fuel filter and charged the battery back up so I can hit the ground running.

I will absolutely do the test suggested by Frankenchevy to eliminate the fuel pump as an issue. Might as well if I am replacing the fuel filter.

See you all at the weekend ha.

 

[Challis350]

Good morning everyone.

SHE RUNS AND SHE SOUNDS BEAUTIFUL!!!!

All I did was replace sender and put in new hoses. Started after fairly limited persuasion actually.

I suspect it was just kinked hoses in the end. Thank you all so much for the advice!

What a great start to the weekend, and the world cup starts tomorrow!!

Now time to install my new radio...

 

[Challis350]

Edit: No she doesn't. The tank is back up but now she is obviously starved of fuel again.

So when the tank is on the floor, she runs beautifully. I then install the tank and she runs immediately afterwards (I suspect that it was just running on the fuel in the lines). This morning I go outside to turn her on and nothing. Cracking, the odd sputter but ultimately no turning on.

I climb underneath the truck and I can freely wiggle the fuel lines so they are not crushed.

Is there any chance the lines are too long and winding? They currently do a loop exiting the fuel tank and connecting to the fuel line. Maybe my pump is not performing as expected, but then why would it work when the tank is on the floor?

This is infuriating!