C3 corvette not getting fuel to carb?

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
I have a 73 with rochester q jet. not getting fuel out of line at carb. I had the carb off waiting for a rebuild and fuel did come out of line (no the engine wasn't cranked over) it just flowed out. Now that the rebuild carb is on, I can't get fuel to flow to it. I replaced the rubber lines from both fuel lines to the pump and tried priming at carb. Still no luck with fuel feed. Is this an indication of a bad pump? Should fuel have flowed out of the line when the carb was off the car or is this a pump issue? Thank you

having a fuel pressure test gauge helps
vgauge.gif

you did not mention which engine you have,
you did not mention
refilling the fuel tank so the pump has a supply of fuel to draw FROM?
obviously the first steps to dump 5-10 gallons of fresh fuel in the fuel tank


http://garage.grumpysperformance.com/index.php?threads/transporting-limited-amounts-of-fuel.11606/


LOGICALLY FOLLOW THE PATH THE FUEL TAKES WITH TESTING
step one

Think logically, and look at the diagrams posted below,, step by step testing will isolate the cause.
is there enough fuel in the fuel tank currently to allow the pump to function, if you can get out a flash light, you'll want too visually check in the fuel tank, adding 5 gallons of fresh fuel certainly would not hurt either. obviously if you have several gallons of fuel,in the tank and its not flowing through the fuel feed line, feeding down too the fuel pump , and/or the fuel strainer sock in the tank is blocked . too test it you'll probably want to force some high pressure air from a compressor back from the fuel pump feed line towards the tank to see if you get bubbles back at the tank, if you do I.d suspect the tanks got considerable trash or rust blocking the fuel flow strainer out of the tank, that needs to be cleaned out, and you may certainly want to replace or clean the fuel tank and fuel lines.

step two
pull the feed line off the manual pump and see if fuel drains, if it does but flow is rather minimal replace the fuel filter if you have one located before the fuel pump (most c3 won,t have this), if fuel flows easily , your fuel pumps likely to be defective as it should prime easily.
you should be able to use a compressor to force high pressure air back through the fuel feed line and easily hear it bubble in the fuel tank if the fuel feed lines clear

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read thru similar thread

http://garage.grumpysperformance.co...ing-down-a-fuel-flow-problem.8505/#post-32546

http://garage.grumpysperformance.co...-wonder-whats-inside-a-manual-fuel-pump.5365/

http://garage.grumpysperformance.com/index.php?threads/setting-up-your-fuel-system.211/

http://garage.grumpysperformance.com/index.php?threads/fuel-pressure-regulators.635/

http://garage.grumpysperformance.com/index.php?threads/fuel-pump-push-rods.11093/

http://garage.grumpysperformance.com/index.php?threads/return-line-too-small.10665/#post-54055

http://garage.grumpysperformance.com/index.php?threads/how-big-a-fuel-pump-do-you-need.1939/


READ THIS
http://static.summitracing.com/global/images/chartsguides/1/199r10660.pdf
SBC PUMP
sum-250020-1_w.jpg

http://www.summitracing.com/parts/sum-250020-1/overview/make/chevrolet


BBC PUMP
SUM-250022.jpg
 
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