Stranded… could use some ideas.

[Rusty Nail]

Nope, my blazer has a length of submerged hose inside the tank, towards the sender.

Here is the problem in my Blazer.

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[SirRobyn0]

Nope, my blazer has a length of submerged hose inside the tank, towards the sender.

Here is the problem in my Blazer.

You must be registered for see images attach

Yes, but your Blazer is injected, and that is typical of a fuel injected vehicle. I assumed based on the video that his is carb'ed. It would be good if the OP specifically said if it is injected or carb'ed for clarification.

If it's injected it'll have the little rubber hose like yours does and a air leak is unlikely because so much of the fuel system has pressure in it.

If it's carb'ed the pick up tube will be metal all the way from the top to the pick up screen / sock. With the fuel pump on the block it can suck air in from anywhere before the pump. If it's a rusty rig it could have rust though the metal lines, if not it's probably a bad bit of rubber hose. As I said earlier if the sock is clogged it'll exacerbate an air leak as it'll suck air or fuel from where ever is easiest.

 

[7900_Blazer]

Pretty interesting… after dropping the tank and confirming all is pristine inside the tank, replaced all the rubber hoses and pressurized the line; held pressure as it should. Decided though to upgrade to an electric fuel pump but leave the original system in place as a backup if I ever need it.

I’ll post an update of the new fuel pump setup.

 

[Bextreme04]

Pretty interesting… after dropping the tank and confirming all is pristine inside the tank, replaced all the rubber hoses and pressurized the line; held pressure as it should. Decided though to upgrade to an electric fuel pump but leave the original system in place as a backup if I ever need it.

I’ll post an update of the new fuel pump setup.

That's not an upgrade.... ask anyone that has been forced to run an electric pump on their rig and they will tell you what an absolute PITA it is. They are well know to fail regularly.

If you are running an electric, it should be as close to the fuel tank as possible, and preferably mounted below the level of the tank because the low pressure electric pumps prefer to push rather than pull and they will burn up fast if they have to pull fuel uphill out of the tank for any amount of time. They are also pretty sensitive to heat, so keep them away from the exhaust also.

 

[TX87R10]

Pretty interesting… after dropping the tank and confirming all is pristine inside the tank, replaced all the rubber hoses and pressurized the line; held pressure as it should. Decided though to upgrade to an electric fuel pump but leave the original system in place as a backup if I ever need it.

I’ll post an update of the new fuel pump setup.

Glad to hear it worked out.

 

[SirRobyn0]

That's not an upgrade.... ask anyone that has been forced to run an electric pump on their rig and they will tell you what an absolute PITA it is. They are well know to fail regularly.

If you are running an electric, it should be as close to the fuel tank as possible, and preferably mounted below the level of the tank because the low pressure electric pumps prefer to push rather than pull and they will burn up fast if they have to pull fuel uphill out of the tank for any amount of time. They are also pretty sensitive to heat, so keep them away from the exhaust also.

I agree, but also adding an electric pump will probably get him home, but will depend on what issue he is band aiding.


Years ago I bought a 77 Class C on a Dodge chassis. These rigs never came with return lines. Apparently to reduce vapor locking the former owner installed a electric pump back by the tank and also left the mechanical pump on the block. I had that electric pump fail twice on trips, both times the mechanical pump was able to pull some fuel though it but not enough to really be able to drive it much so it required bypassing it on the side of the road. First time was a PITA because I had to diagnose the issue first. The second time, it was more like oh ya, after the second failure ditched the electric pump and fixed the vapor locking issues by installing a return line.

OP, the thing about the pressurizing the lines is it is possible to suck air but not have noticeable amount of air leak out. At the shop, we'd drop the tank like you did to inspect and replace all the rubber. I'm quite sure adding an electric pump will get you around and back home, and probably around some more, so for that reason I think it's a great idea to get you going again, depending on the issue, and be mindful that if you have a weak line it may at some point start to leak with pressure in it. Do yourself a favor, if this is going to be a rig you drive a lot / take on trips, when you get back home diagnose the issue and fix it properly.

 

[Rusty Nail]

Ive never seen a plugged up sock in my life..

I find it really hard to believe this could be the 2nd wiped fuel pump lobe in a week!
What brand of motor oil to you run @7900_Blazer ??

Nobody ever asked that other guy but we oughta find out!

 

[SirRobyn0]

I don't think it's a wiped lobed. I say that for two reasons, one is it's just not that common, and the other is if you think back to his video, it looks like he is getting air and fuel into the filter. I think if it were a wiped lobe we'd just see a lack of fuel, but if it were me once back home I'd check the lobe anyway as it's relatively easy to check.

 

[SirRobyn0]

Ive never seen a plugged up sock in my life..

Maybe it has to do with the moisture here from the weather? Not sure, but you can't be to far away from me since my mom only lives a mile away lol

 

[Rusty Nail]

 

[7900_Blazer]

So a quick update. Put the electric pump on, replaced the lines on top of the tank, blew out everything… got about a block and again, no fuel, dead in the middle of the street. I know it was getting no fuel because I disconnected the fuel line at the carb and turned on the key. The pump was activated but no fuel pumping out.

Disconnected everything, hooked the gas can in the floorboard back up to the mechanical pump via a temporary line, cranked up and drove like it should.

There is one 5” or 6” section of rubber fuel line in the middle of the frame, maybe it is collapsing under load from the pump but it doesn’t feel super soft, although it probably is 46 years old. Going to change that out and see what happens.

 

[7900_Blazer]

Question, is the sending unit inside the tank a solid line? Is there anything inside it that could wear out and collapse or is it a simple solid tube with a sock on it?

Also, the sock on the end of the pickup tube is a mesh right? Seems impossible for it to somehow seal up enough to stop up the whole line???

Just seems like this shouldn’t be brain surgery to get gas from the tank to the carb… crazy frustrating.

 

[7900_Blazer]

Worst case scenario, could I run temporary rubber fuel line parallel with the steel line, from the tank to the fuel pump if that steel line has maybe a rusty pinhole somewhere which is allowing air?

 

[7900_Blazer]

So more info. Hooked up a fuel pressure gauge. Cranked it, had roughly 7 psi. Ran the RPMs up to 2200 or so, fuel pressure held for 30 seconds or maybe 45 or a bit more, then the fuel pressure declined declined declined, finally to zero and it died… so clearly a supply restriction somewhere from the fuel pump back to the tank.

Engine was basically cold… it probably got up to 150 or 160 degrees…

If I sit and wait, it’ll likely crank again, then again eventually die.

 

[SquareRoot]

So more info. Hooked up a fuel pressure gauge. Cranked it, had roughly 7 psi. Ran the RPMs up to 2200 or so, fuel pressure held for 30 seconds or maybe 45 or a bit more, then the fuel pressure declined declined declined, finally to zero and it died… so clearly a supply restriction somewhere from the fuel pump back to the tank.

Engine was basically cold… it probably got up to 150 or 160 degrees…

If I sit and wait, it’ll likely crank again, then again eventually die.

Repeat that with the gas cap removed.