Stranded… could use some ideas.

[7900_Blazer]

If the truck has sat any measurable time with ETHANOL in the gas tank, I believe it is VERY likely the pickup hose has failed - inside the tank. Which leads to the pumping of the air.

All you gotta do is drop the tank and change the two dollars worth of bulk rubber fuel line. Easy Peasy!

I suspect this is the problem. Tomorrow morning (it’s almost 10 pm here) I’m going to pull the tank line off the pump and run a new line into a 5 gallon gas can and see how it runs. My guess is it will run fine, which will isolate the line to the tank and the tank itself.
I hate to have to drop the tank in the street in front of my son’s house (he’s renting a room from a friend), but if that solves the problem, so be it.

 

[Rusty Nail]

Me too...but if it'll run off a 5 gallon can, you could simply drive it to a more friendly place, no? Heeeeeyyy!

 

[7900_Blazer]

Me too...but if it'll run off a 5 gallon can, you could simply drive it to a more friendly place, no? Heeeeeyyy!

Absolutely, just not sure where that is in Colorado Springs…

 

[73c20jim]

Large change of elevation???

 

[7900_Blazer]

Large change of elevation???

yes, North Texas to Colorado Springs, however, I actually picked up this basket case in Denver last summer… so it’s ‘from here’ so to speak.

I’m dreading dropping that tank in the street… any tips or tricks?

 

[SirRobyn0]

I'm coming along late, but will add this. Looking at your fuel filter video I agree it does not look normal. If it does this again put your hand on it, obviously it's going to be warm, but if it's boiling it's going to be to hot to touch. Typically vapor lock (from boil of fuel) occurs inside or just before the fuel pump, not after in the feed line to the carb, the reason being is that between the pump and the carb the fuel is under pressure and that pressure raises the boiling point of the fuel. So often times (but not always), in a rig that is vapor locked or trying to vapor lock that has a filter like yours, you'll just see the fuel amount drop in the fuel filter until it stalls, because the fuel is boiling in the pump, but not in the line in front of the carb, because the pressure turns the vapor back into liquid.

My point, looks like air to me as well. In the tank is likely. but it can suck air in anywhere there is rubber line before the pump, so look and replace any marginal looking rubber. Also a clogged sock in tank will exacerbate any air leak, because it'll suck air or fuel from wherever the least resistance is.

yes, North Texas to Colorado Springs, however, I actually picked up this basket case in Denver last summer… so it’s ‘from here’ so to speak.

I’m dreading dropping that tank in the street… any tips or tricks?

Not really, figure out a way to get as much fuel out as possible less weigh will make the job much easier.

Plan to replace ALL the rubber hose on top of and inside the tank while you have it out so you don't have to do it a second time when you get back home.

 

[Rusty Nail]

xc_hide_links_from_guests_guests_error_hide_media

It's only a 15mm socket (9/16) and a pair of 3 inch extensions on a ratchet.
Prolly gonna need a floor jack and a piece of 2x4.
I don't think it'll be bad for you at all..it'll be fun, i'm kinda jealous in truth..having to make another trip to (wherever) for something else would suck air too though.
No pressure!
It's very straightforward. A #2 flathead and an 8oz. hammer for the lock ring..same screwdriver for the hose clamps..
Could ya use the spare to take up slack? It's just a ****** piece of bulk 3/8 rubber fuel line not four inches long , you'll see it split easy and it will be a huge relief - simple to fix.
Don't sweat it too much.
I disagree with my friend however, and do not believe the side of the road is an acceptable spot for preventative maintenance and I sure as hell wouldn't touch anything unnecessarily or take any gas out I didn't have to...it's too late for that now lol...I would much rather do it ALL again at home. BUT! There's a lot more room under there than you think...I dont know about your Blazer but I would be trying to drop the tank on top of a spare tire if I could. It's a loooooong way up there from the dirt! and you could likely pass your spare tire underneath the truck - use that to your advantage, it's your workbench.

You really only have to drop one side to get the sender out but the lock ring - the straps hang from one side, driver?, put the tire over there to hold the gas weight and put the jack on the other side (of the tank), that's the side you work from. Passenger I believe.
Dont gotta take the tank all the way out, we're only after the sender okay? We just need that part from the tank, it's not hard to sneak by. The flag time to change one sure aint much. Half an hour? One hour.

Dude! A screwdriver, a hammer, and a ratchet. Three tools.
You got the jack and a piece of wood?
Four.

Four tools, one hour.


Ready?

GO!


Safety first kids!













*edit*
We're gonna need some pictures of this alleged "round eye" Blazer while you're at it btw p.s.

 

[7900_Blazer]

xc_hide_links_from_guests_guests_error_hide_media

It's only a 15mm socket (9/16) and a pair of 3 inch extensions on a ratchet.
Prolly gonna need a floor jack and a piece of 2x4.
I don't think it'll be bad for you at all..it'll be fun, i'm kinda jealous in truth..having to make another trip to (wherever) for something else would suck air too though.
No pressure!
It's very straightforward. A #2 flathead and an 8oz. hammer for the lock ring..same screwdriver for the hose clamps..
Could ya use the spare to take up slack? It's just a ****** piece of bulk 3/8 rubber fuel line not four inches long , you'll see it split easy and it will be a huge relief - simple to fix.
Don't sweat it too much.
I disagree with my friend however, and do not believe the side of the road is an acceptable spot for preventative maintenance and I sure as hell wouldn't touch anything unnecessarily or take any gas out I didn't have to...it's too late for that now lol...I would much rather do it ALL again at home. BUT! There's a lot more room under there than you think...I dont know about your Blazer but I would be trying to drop the tank on top of a spare tire if I could. It's a loooooong way up there from the dirt! and you could likely pass your spare tire underneath the truck - use that to your advantage, it's your workbench.

You really only have to drop one side to get the sender out but the lock ring - the straps hang from one side, driver?, put the tire over there to hold the gas weight and put the jack on the other side (of the tank), that's the side you work from. Passenger I believe.
Dont gotta take the tank all the way out, we're only after the sender okay? We just need that part from the tank, it's not hard to sneak by. The flag time to change one sure aint much. Half an hour? One hour.

Dude! A screwdriver, a hammer, and a ratchet. Three tools.
You got the jack and a piece of wood?
Four.

Four tools, one hour.


Ready?

GO!


Safety first kids!



*edit*
We're gonna need some pictures of this alleged "round eye" Blazer while you're at it btw p.s.

Thanks for the help! I dropped the tank on my ‘71 and it sucked… This ‘75 has hitch-brackets built around the tank, not sure yet what it’s going to take to get that all off first.

Here are two pics, one being a kick in the huevos…

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[7900_Blazer]

Runs great off the gas can sitting in the floorboard.

so likely the pickup is simply stopped up with trash or would you suspect something else?

 

[Scott91370]

If it is running with the gas can I would say definitely trash in the line backwards from where you disconnected it. Looks like you only have one fuel tank so it wouldn't be in the switching assembly.
Blow some compressed air backwards to clear the line but you'll probably still want to drop the tank to clean out the debris.

 

[7900_Blazer]

Dropped the tank… no trash :-(… really clean in there… so has to be a leak between the tank and the pump, OR it has all of a sudden started vapor locking…

 

[Grit dog]

If the truck has sat any measurable time with ETHANOL in the gas tank, I believe it is VERY likely the pickup hose has failed - inside the tank. Which leads to the pumping of the air.

All you gotta do is drop the tank and change the two dollars worth of bulk rubber fuel line. Easy Peasy!

I've not seen a fuel pickup that has any hose "in" the tank unless maybe its jerry rigged. Fuel pickup is a steel line from bottom to top.
Or did I misunderstand your post?

 

[Bextreme04]

Dropped the tank… no trash :-(… really clean in there… so has to be a leak between the tank and the pump, OR it has all of a sudden started vapor locking…

I would bet you have some leaky rubber somewhere. Since you dropped the tank, did you replace all of the rubber fuel line between the sending unit and the pump? There should be a few sections of rubber in there.

I would also look into adding in a return line, it makes a big difference if you are driving it around in hot weather.

 

[Grit dog]

No offense, but have you topped the tank off? The tanks don't have baffles and mine will act like its running out of gas going up a steep hill on less than a quarter tank. I would not trust the gas gauge either. Do you have dual tanks, is it switching tanks correctly and doing this on both tanks? My tank valve went bad and would not fully switch tanks.

Possibility, but steep hill is relative and he was on I 25 with some short, maybe 3-4% grades after topping Raton pass.


Although if fuel inlet sock is partially plugged with trash, less fuel in tank puts less head pressure on the inlet (again, small, about 1/4 psi from full to empty)

OP, try blowing out the fuel line back into the tank.
If it's boiling it won't do it once cooled down. Plus if boiling fuel, you may/would have experienced vapor lock already.
If the bubbles don't go away when cool then it's an air leak in fuel line from tank. Could even be in the tank and submerged when tank is full.
Not knowing condition of your truck, only you know the propensity for cracked hoses or rusted out fuel lines.

 

[Grit dog]

Sorry, missed you posted that you just dropped the tank. So it apparently didn't run when cooled down either? But runs off a jerry can and hose. That most likely = air leak somewhere in the line to the pump.
And didn't watch the video but SirRobyns post, yes, the fuel would boil before the pump first, not after the pump usually.

Good luck man!