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Rochester carb not pulling fuel

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Bongdozer

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Earlier last month I inherited a 1978 blazer, it was very rough but once it fired up it ran very well. Fast forward I got it able to move from where it was at to a more convenient location, drained the tank put a few gallons in and moved it about 1/2 a mile. Ran fine, got to the destination and it sputtered and died, I could keep it running with my foot, and parked it where it sits now. Assumed it was either the fuel lines, the carb or vacuum lines (the vacuum lines were dry rotted and with a little manipulation would crumble.) I ran a brake cable and drill through the fuel lines and remounted them, they blew through MUCH better, I assumed then that that was probably the issue. But being how I am I rebuilt the carb, i didn’t change much just the base gasket, main, the accelerator pump, both the needle and seat and cleaned everything in the main body up. Important to note, I only disassembled the main body. I am not familiar with Rochester’s at all so I didn’t want to bite off more than I could chew. That being said everything I inspected looked clean and tidy. With how well it ran, I didn’t even check the float level again I didn’t want to muck it up, being that I knew that seemed to work.

So now the vehicle can run if I fill the bowl manually, the lines are clear it gets fuel all the way to the carb fuel inlet. I previously switched the fuel filter out for a clear
 
Clear fuel filter so I could see if anything was coming out of the tank I might have missed (the brake line I used was about long enough to reach halfway on both sides) it had a bit of rust sediment but not a ton.
If I blow on the fuel inlet hose straight to the carb, it feels blocked.

I was wondering if anyone had an idea of if I should be looking at the main body? Or something else? I took the carb off for disassembly again.

If it’s not something from the carb, either main body or auxiliary. I’d have my money on the vacuum lines either not being hooked up correctly, or them dry rotting and blocking a hole with debris.

Any thoughts?
(Edit) also from what I can tell it’s running about the same as when I parked it from the drive, I don’t think my disassembly of the carb changed anything.
 
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Welcome @Bongdozer

If your getting fuel all the to inlet at carb, then I hate to say this but the air horn will need to come off again. I suspect the needle and seat are jammed closed.
Q jet float level is very forgiving most will run with 3/8" range, and is easy to check, not hard to adjust. Little tricky to get the the float, needle clip, primary metering rods and float block all together at same time but is doable.

One important note do not crank down on the front 2 bolts this will ruin a Qjet.
 
Wes Harden said:
Welcome @Bongdozer

If your getting fuel all the to inlet at carb, then I hate to say this but the air horn will need to come off again. I suspect the needle and seat are jammed closed.
Q jet float level is very forgiving most will run with 3/8" range, and is easy to check, not hard to adjust. Little tricky to get the the float, needle clip, primary metering rods and float block all together at same time but is doable.

One important note do not crank down on the front 2 bolts this will ruin a Qjet.
Click to expand...
Glad my intuition was right on the screws they all seemed barely snug, so I readjusted the same.

I’ll take the main body off once more and have a look at the needle and seat. The instructions I got with the rebuild kit were… lackluster. lot of cut offs and missing words. The diagrams looked like black blocks.

When I attempt to adjust the float/needle and seat, should the needle already rest lifted off the seat? Or is there a measurement you can give me to reference? I have the L ruler in the kit but no instruction for it. Where does that 3/8”s come into play?
 
so when checking the float level, leave the metering rods, and block out. Gently push the needle down into the seat with your finger. the measurement is taken at the tip of the top of the float, there is sometimes a line on top where you want to measure. If you post the carb number can look it up, but 1/4" to 3/8" below the edge of the bowl is good.
 
RaisedK5 said:
I see where you have a clear filter in the fuel line, but did you change the filter in the carb itself?? The one in the inlet housing?
Click to expand...
No, but once I reinstalled it and it happened I pulled it off and cleaned it out and put it back in, it seemed to blow through ok. That is where the blockage seems to be though. I have a new one, at the time I didn’t know where it went from the rebuild kit, I’ll change to the new, but I don’t think that is the issue.
 
yeah I Mostly remove that little check valve, not to concerned about drain back, with and electric pump.
 
yes sir if the inlet filter in correct and clear. then the needle and seat are next.
 
If anyone searches and finds this thread it was the float, I took it out as gingerly as I could, but must have bent it in on accident. Now I have an idle issue I have to track down. Some vacuum canisters that have cracked off from the hose. If anyone, can identify which this is and what it goes to much appreciated. (Nvm I don’t have photobucket) that being said I’m going to do a quick search for a vacuum diagram.

Thanks for the help with the float, guys.
 
After some research and replacing my top gasket in my carb, I’ve chased all my problems down to the vacuum lines, I’ve taken some pictures for reference if anyone can help me identify these lines and where they go it would be much appreciated. I tried a search online with a few different tries and got most of my vacuum lines sorted minus a few.

I’m sure some of you guys can probably name these by feel and smell, but I hope pics will suffice
 
This first is two vacuum canisters passenger side, both have all of their hoses scrambled and dry rotted out.
 
Then there’s this, a vacuum hose coming from a charcoal canister?? I think. The truck was/is in rough shape, kind of piecing it back together.
 
And lastly, this hose, I initially thought it went to my top air horn in the carburetor but now I think it goes to the underside of my air cleaner, and that would mean my air horn on the carburetor is open, which is why I think my idle is all messed up.
 
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