Need fueling help

[PnwK20]

I'm running out ideas on why I'm not getting fuel.

1977 Chevy k20 Cheyenne 350 with carter 4bbl and 4 speed manual w/granny low

I was driving home from work one day and my truck started acting like it was out of fuel but then it went to normal and I drove a couple more miles and it did it again for couple more miles it was fine and then finally shut off. Got it home and tested for spark and spark is fine and then tested fuel, I'm not getting any fuel to my carburetor. Replaced the fuel pump and lines to the carburetor and new clear filter. Used a syringe to fill the bowl through the vent and it started for a brief second and shut off. Still no fuel in the filter, I have dual tanks and they both have fuel. The only thing I have not tried yet is inserting a compressor nozzle into the line and blowing to see if debris out. Is there something I am missing? Any other ideas you can think of?

All help is greatly appreciated

 

[crazy4offroad]

If original float assemblies the pick-up tube(s) could have a pin hole. I would replace all the rubber lines and blow out the hard lines. Use polypropylene fuel line line, as the new ethanol-gas deteriorates rubber.

 

[Geektrucker]

In the worth a try category... Have you tried by-passing the tank switch? Are both tanks giving you a fit, or just one?

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[PnwK20]

The carter carb is less than a year old, the pump and the hoses from pump to the carb are all 3/8 fuel line. Even if I take the like off the pump that goes to the carb and turn it over no fuel comes out of the lines

 

[PnwK20]

In the worth a try category... Have you tried by-passing the tank switch? Are both tanks giving you a fit, or just one?

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Both tanks are giving me problems

 

[gmachinz]

You have clogged lines-prolly rust, dirt etc. in the main line to pump. If the tanks are original, I am willing to bet that's your problem.

 

[crazy4offroad]

I changed both sending units in dad's tanks last year, the "socks" on the pickup tubes looked like they were full of varnish. I'm sure there was some restriction there.

 

[da_raabi]

I'm betting this has something to do with the switching unit. Mine let go and did the same thing right after I bought my truck. I just bypassed it with some fuel hose and I've been good to go ever since. My $$ is on that.

And x10000000 on the fuel hose suggestion. I've got a write-up on it in the engine section. You need to be using "fuel injection hose" as the old rubber stuff practically dissolves in the new ethanol fuel. I discovered this when I had a real bad fuel smell in the engine bay, popped the hood and found fuel pooled all over the frame, engine crossmember, etc. Keep in mind the fuel hose was less than a year old... Yeah. Not good.

Edit: Here is my write-up on the subject: http://www.gmsquarebody.com/forum/showthread.php?t=13208

 

[highdesertrange]

sounds like you are sucking air. you just need to find out where. have you tried to disconnect the feed line to the fuel pump and run it straight into a gas can? highdesertranger

 

[PnwK20]

Sorry for the absence, I haven't had the opportunity to monkey with it yet, hopefully over the weekend