Fuel Tank Conversion, no fuel to carb

[melon8657]

Over the weekend I installed the underbed fuel tank conversion on my 1969 c10 (Longbed) from LMC. We have put around 7gal of gas in fuel tank, gauge is actually reading 1/4tank but I am not getting anything at the carb. I have about 1.5ft - 2ft of rubber line from fuel tank to 4ft of metal line, then 6inches of rubber, fuel filter, 4inches of rubber then factory metal to the mechanical fuel pump, metal from fuel pump to carb. Last night I blew through factory metal lines with air compressor to make sure they weren't plugged up. Tonight I replaced mechanical fuel pump, and back blew from fuel filter to tank. Still not getting any gas to the carb.

What am I missing? Is there to much distance from mechanical fuel pump to the new fuel tank? Do I need to install an electric fuel pump close to the tank?

[midniteblues]

I had a problem priming a new tank,and line install once,
I disconnected the fuel "in" line at the pump and put a bucket under it then cupped my hand over the fuel filler an used the air threw my cupped hand the pressure pushed the fuel though the line I heard it runnig out and then
I quickly reconnected the fuel line and cranked it a little then it started fine.

I thought I was going crazy not getting any fuel up to the carb oh an I killed the battery trying too

[sharpmark]

a mechanical fuel pump in good condition should pump fine from the tank as long as air doesn't get in.just done this on my truck.make sure all rubber to pipe connections are good!
couple of things to try-when you blow back thru the lines into the tank- can you hear the fuel bubbling? if so that will tell you the fuel pickup pipe is under the fuel level.if not then your pickup pipe has a problem.
another way to try is to block off the vent pipes in the tank and remove the first length of rubber from the 4ft of metal pipe and then put a rag around your air gun and pump some air into the filler pipe-fuel should come out of the rubber hose.WARNING donot put much air in or you could balloon your tank or squirt fuel everywhere.
if this works then you have to work your way down your delivery line looking for the problem.
good luck
mark

[melon8657]

Thanks for the replies, I did get it going last night. After reading replies about possible air in lines I used a Mini-Vac system we have for bleeding brake lines and a pair of hemostats. I disconnected rubber line from fuel pump and hooked Mini-vac up to the metal line there, then using hemostats crimped off rubber line by the fuel filter (this way I could see gas coming through filter if it was working). After about to cycles of doing this the pint container on the mini-vac was full of fresh gas. I then disconnected mini-vac, hooked up the the rubber and metal lines by the fuel pump, and disconnected the fuel line from carb. After fuel line at carb was disconnected I poured gas from mini-vac container into the line that runs from fuel pump to carb, reinstalled line and she started without any hesitation. Thanks for the input.

[melon8657]

still having problems getting fuel to carb. Since the truck is at my in-laws, which is 20 miles away and chasing my kids around with soccer, softball, and cheerleading it has been 2 weeks since I was able to get back to it. This weekend I had no fuel to carb AGAIN, had to do the same routine I did last time. Checked under truck and there are no fuel leaks and all hose clamps are tight. Wondering if electric fuel pump is the way to go??!!

[Tynee]

Originally Posted by melon8657

Wondering if electric fuel pump is the way to go??!!

In my experience, no. They are noisy and unreliable. I've never been so happy to finish a project as I was the day I converted mine back from electric to factory mechanical. I don't have the tank under the bed, it's still behind the seat, but I would suggest doing everything else you can do BEFORE you add an electric fuel pump to the syste.

[mrein3]

In this situation I always "prime the pump" by pouring a little gas in the carb then turning the key. My theory is that the engine firing and spitting on that gas I poured down the carb works the fuel pump WAY more than just turning the pump with the starter motor. Not only do you need to fill the fuel lines but you also have to fill the carb bowl(s).

Just be careful. A little gas down the carb goes a long way.

[GASoline71]

What mrein3 said...

Gary

[melon8657]

Thanks everyone, I will hopefully get to try that extra bit of adding fuel directly to the carb on Wednesday.

[SS Tim]

If it didn't have enough gas left in the lines and the carb bowls after running normally then sitting about two weeks I'd say there are leaks in the system allowing the fuel to siphon back into the now lower tank. Also to back fill a line, a bowl or prime a long sitting engine I've found a restuarant ketchup style squeeze bottle with the tapered capable end works great.