fuel issue

[RdHuggr68]

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]

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


http://www.summitracing.com/nv/search?keyword=fuel%20check%20valve

[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.

[GregWeld]

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]

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]

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. :headscratch:
Kevin

[dontlifttoshift]

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

[RdHuggr68]

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

I thought the same but I heard him try to start it last weekend and it took about 45 seconds of cranking to start He turned it off for about 30 minutes and it started right up. He said it always does the same thing.
Kevin

[GregWeld]

I'm intrigued by this whole thing.

Even a carb car - properly tuned - should fire right up. I've never had to crank one for 45 seconds... so something is wrong. The hard part is not being there live... to try to diagnose an issue like this.

First thing I'd check is the initial timing... Not sure we know what motor this even is.

Does it have a ballast resistor still in the system?

Have you checked the spark on crank?? There's various ways to do this.. but assume someone there knows how.

If you pull the air cleaner off -- and pump the throttle... do you see gas squirting?

I'm wondering - if after it's started the first time.... does it start right up after that like it should??

Has anyone tried starting fluid for it's initial fire up after sitting?? If so - does it fire right off and keep running??

Is the fuel fresh?? Fresh meaning in the last 60 days.

[JpRngr]

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.

[RdHuggr68]

I'm intrigued by this whole thing.

Even a carb car - properly tuned - should fire right up. I've never had to crank one for 45 seconds... so something is wrong. The hard part is not being there live... to try to diagnose an issue like this.

First thing I'd check is the initial timing... Not sure we know what motor this even is.

Does it have a ballast resistor still in the system?

Have you checked the spark on crank?? There's various ways to do this.. but assume someone there knows how.

If you pull the air cleaner off -- and pump the throttle... do you see gas squirting?

I'm wondering - if after it's started the first time.... does it start right up after that like it should??

Has anyone tried starting fluid for it's initial fire up after sitting?? If so - does it fire right off and keep running??

Is the fuel fresh?? Fresh meaning in the last 60 days.

350 small block, aftermarket cam , headers, the dreaded Edelbrock Performer carb.
No ballast resistor, I don't know about timing or seeing gas squirting in carb when operating linkage. I saw him start it right up after initital hard start. Has not tried starting fluid yet. Fuel was not real fresh, he did'nt give me a time frame but said not that fresh. I told him to pull the top of the carb off when he gets back from CA. Thats all I have will update when he gets back.
Kevin

[GregWeld]

350 small block, aftermarket cam , headers, the dreaded Edelbrock Performer carb.
No ballast resistor, I don't know about timing or seeing gas squirting in carb when operating linkage. I saw him start it right up after initital hard start. Has not tried starting fluid yet. Fuel was not real fresh, he did'nt give me a time frame but said not that fresh. I told him to pull the top of the carb off when he gets back from CA. Thats all I have will update when he gets back.
Kevin

It would be interesting to see if it fires right up with a squirt of starter fluid...

It would also be interesting to see if it kept running after it fired off (if it did fire right off with the starter fluid).

Old gas can be a problem - by old - I mean 4 or 5 months....

Would be sad to chase a problem - only to find out it's just old gas....

[RdHuggr68]

It would be interesting to see if it fires right up with a squirt of starter fluid...

It would also be interesting to see if it kept running after it fired off (if it did fire right off with the starter fluid).

Old gas can be a problem - by old - I mean 4 or 5 months....

Would be sad to chase a problem - only to find out it's just old gas....

Keep ya posted when he gets back and we can look at it. Might have to try the starting fluid. Now you have me curious!:thumbsup: :thumbsup:
Kevin