Fuel draining out of the inlet line

[CruzinHigh]

Need some help guys.

I am not much when it comes to working on carbed stuff, but hopefully I can work through this.

I got my truck up and running now after all the recent repairs and modifications.

All I really did to the motor though was to re-do the fuel system from tank to carb. Pulled the fuel tank and replaced the sock filter, replaced all the fuel hoses, replaced the fuel pump, installed an inline clear filter, braided hose kit from filter to carb, and then the t fitting you see here in the photos so I could add the fuel pressure gauge.





# 1 problem that I have come up with is that the fuel immediately drains back down out of the line after shut down. I know this because I see that clear little filter start emptying toward the tank direction right away.
That's not normal is it?

# 2 the pressure gauge isn't doing Jack.. You guys think it is because of the location I have chosen to T the connection at and therefore the carb just sucks in all the pressure? Shouldn't matter should it, pressure should be the same throughout the system?  Usually carbed systems run around 6 psi right?

# 3 the motor idles perfect. But try to go run it down the road and I can barely get it out of first before cough... cough... sputter.. dies.

It ran pretty good before I did the work on the fuel system, but now its quite different.

It almost sounds like a plugged jet in the carb to kill it like that? I am sure I will need to check out the float settings, etc. Just wanted to see if any of you guys had any idea. Especially about the draining fuel condition.

By the way there are NO leaks anywhere in the system. At least for that I am happy!

[shpark2]

I got a similar setup with in-line filter, although a bit more farmyard looking.  I notice it drains slowly as well after running, but I have no problems starting/idling/flooring it(as I found out on weekend).  I think, and this is purely a guess - it drains through the return line to tank until there is no fuel above the fuel pump.  Someone here will set me straight if that's wrong, regardless it should still leave some fuel in your float to start, right?  It shouldn't take long to juice the line between the pump and carb as it turns over, I know mine pumped 20' of empty fuel line full and started in about 15 seconds after I replaced the fuel line and cleaned my tank.  I guess you could always put a check valve in.

[Captkaos]

# 1 problem that I have come up with is that the fuel immediately drains back down out of the line after shut down.
That's not normal is it?

Yes that is normal.

# 2 the pressure gauge isn't doing Jack.. You guys think it is because of the location I have chosen to T the connection at and therefore the carb just sucks in all the pressure? Shouldn't matter should it, pressure should be the same throughout the system?  Usually carbed systems run around 6 psi right?

I can't tell where the gauge is, but it should be inline to the feed line, not branched off.  If it tees and on the tee is the gauge and then feed on the other end, it should be ok.  Carbs need 5-7lbs max at "top" speed.

# 3 the motor idles perfect. But try to go run it down the road and I can barely get it out of first before cough... cough... sputter.. dies.

Where is the float level?
Is the only thing that change in the actual maintenance was the filter sock and the inline filter?
Did you run the carb any before adding the filters?

[CruzinHigh]

Ok thanks guys, I think you're close to setting me straight on this one.   Sounds like I need to verify what is going on with float level for sure.

Yep, all I did really was add the new fuel lines and the pressure gauge, plus remove and reinstall the tank. 

I can't help but wonder if that t fitting branched right at the inlet to feed the smaller hose that supplies the pressure gauge isn't causing me some sort of headache.  I guess it isn't going to work properly with that setup, although I am not sure why.  I thought regardless of where the t fitting would end up there is supposed to be a constant 4 or 5 psi in the system wherever you tap in??

[joesgarage71]

 Holley float adjustment here
www.holley.com/data/Techservice/Technical/Adjusting%20Your%20Carburetor.pdf
 Steve

[260z]

You might want to check the choke to make sure it is working correctly. My truck always had to primed if it sat for a few days, could not see any fuel in the clear filter. Choke was only closing half, adjust it and so far no problem. My carb is an edelbrock but could same problem.

[CruzinHigh]

Well, I am back at it with this thing and I have set the float levels now and checked the cranking fuel pressure.  Fuel pressure at cranking is around 5 or 6 psi and it starts and idles good.

The truck still dies out under a load, usually in second gear once you get it up around 20-25 mph.  If I push in the clutch quickly and just barely feather the throttle, it will stay running.  But if it dies, I will have to push the throttle a few times to prime it again to get it started.  Clearly, this thing is starving for fuel huh?

Just to summarize, I did have the tank out and replaced the sock filter in tank.  I also replaced the rubber tank to hard line fuel lines, and the fuel lines from the hard line to the pump.  Then replaced the pump, and all the line up to the carb.

I am gonna run it on a remote tank next, just put a small gas can up in the front fenderwell temporarily to verify it isn't starving for fuel somehow with what I've done in the tank.

[VileZambonie]

Well just check the basics first. Make sure no hoses are kinked. From there check your timing and ignition components. Is your base idle speed too low?

[CruzinHigh]

Yeah, I've got the timing dialed right in, and the ignition should be just fine.  Like you said Vile, I am gonna try to eliminate the basics first.  Pinched fuel line is starting to sound suspicious to me.       Yuk.. I sure hope I don't have to pull that fuel tank again and deal with that.  Sure is hard to reach those lines up there!

[CruzinHigh]

Ok guys, figured it out.   It was indeed a pinched fuel line on the lines from the tank to the frame lines.  The remote tank did the trick and proved to me that the fuel VOLUME just wasn't there...

So I hope we can all learn from my mistake here.  Fuel PRESSURE doesn't necessarily translate to sufficient fuel VOLUME.   

Now I am gonna hook the fuel pressure gauge setup back up again too and see if the gauge in the cab indicates correct now too.

Thanks for the ideas here fellas.