fuel issue - Lateral-g Forums

RdHuggr68 · #1 09-29-2015, 05:11 PM

My next door neighbor has a 69 RS/SS Camaro and it has a return line off of the fuel pump and when he shuts the car off the fuel from the carb starts draining back to the tank. He has to crank it for about a minute to get it started if it sits more than 4 hours. Anybody out there have any solutions?
The fuel pump is mechanical.
Kevin

**GregWeld** · #2 09-29-2015, 08:55 PM

A one way check valve on the line to the carb -- won't let fuel run back out.

http://www.summitracing.com/nv/searc...0check%20valve

dale68z · #3 09-29-2015, 09:26 PM

Are you sure the fuel is draining back? To do that on any carb I know, the fuel will need to climb up, out of the bowel.
If it has a Q jet, it is common for the metering wells to drain into the intake. Will take some cranking to clear the fuel before it will start.

**GregWeld** · #4 09-30-2015, 06:22 AM

Quote:

Originally Posted by dale68z

Are you sure the fuel is draining back? To do that on any carb I know, the fuel will need to climb up, out of the bowel.
If it has a Q jet, it is common for the metering wells to drain into the intake. Will take some cranking to clear the fuel before it will start.

I'd never heard of any car doing this - ever... so I was at a complete loss as to argue what could possibly be the cause. I'm baffled. But... a quick fix - if all other things are as they should be... was the check valve. IDK... beats me!

**clill** · #5 09-30-2015, 06:53 AM

There is a check valve in the mechanical fuel pump that must be stuck open. Replace the pump if it isn't one that can be rebuilt.

RdHuggr68 · #6 09-30-2015, 04:48 PM

Quote:

Originally Posted by GregWeld

I'd never heard of any car doing this - ever... so I was at a complete loss as to argue what could possibly be the cause. I'm baffled. But... a quick fix - if all other things are as they should be... was the check valve. IDK... beats me!

I told him to start it up and let it run for a couple minutes then turn it off and disconnect the return line and see if it drains back. I have seen his glass fuel filter up by the carb was empty both times I looked at it.

Kevin

dontlifttoshift · #7 09-30-2015, 06:19 PM

There should still be fuel in the bowls. The car will run a long time with just the fuel from the bowls.

JpRngr · #8 10-01-2015, 05:49 PM

Quote:

Originally Posted by dale68z

Are you sure the fuel is draining back? To do that on any carb I know, the fuel will need to climb up, out of the bowel.
If it has a Q jet, it is common for the metering wells to drain into the intake. Will take some cranking to clear the fuel before it will start.

Yep, it's not likely that the fuel is going to get sucked out of the bowl. Back in the day, the guy that overhauled carbs at the shop I worked at, would epoxy the plugs in the bottom of the carbs because it was so common for them to leak.