Fuel flow possibly blocked

Gang,  I'm attempting to restart my 4.9L six in the '85 after head work and can't seem to get a good flow of gas.  Lots of eye droppers of gas down the throat of the one barrel and it begins to fire but dies when the gas is burned.  I have a clear fuel filter just before the Moroso electric pump and after lots of cranking, it doesn't show any sign of filling.

Today, I put an in-line, low PSI pump in the fuel line and thinking it would prime the system, was disappointed to see no change in the emptiness of the filter.  Bummer.

I think I'm going to have to siphon out the tank and clean it out.  Should I try to start it using a small container of gas directly to the carb's inlet before dropping the rear tank?

Thanks!

definitely! if you can do a simple test like running a hose into a tank to prove half of the system then you can drop the tank with confidence of finding your problem. you say that you have an electric pump and a visible filter. are you certain that it is running? are you certain of its polarity or directionality. both can be very easy mistakes to make. there is no sense in trying to start the engine unless you see the filter fill up.

Matt - As sure as I can be on the direction of flow, from an arrow on the side.  I'll try to run the engine with an alternate fuel source... figure something out.  Just thinking the tank needs to come down if I'm ever going to drive this truck without a dry mouth.  :-)

then it should be a simple process to divide the two engine and functioning systems. and fuel tank /pickup pick up tube.

mat in tn wrote

then it should be a simple process to divide the two engine and functioning systems. and fuel tank /pickup pick up tube.

Good thinking!  That's the best problem-solving approach: Divide and conquer.  

Gary - When you made the comparison of peeling an onion as we work on our trucks, you was right!  :-)

Reminds me of Roseann Roseannadanna's "It's allllways something!"

Yep, you peel and cry, peel and cry, etc.  But some day you'll have enough to have a Bloomin' Onion!  

Is there a trick to dropping the rear tank?  I've siphoned all I can get and have some boxes to hold it when the bolts are out.  Wish I could lift the bed off, but short of that, it looks like I have a steel line that dead-ends in the engine compartment that appears to be a breather or air escape system.  Can I just separate it from the hose it goes into, up there?

The only "trick" is to raise the bed.  And that's not always easy to do as the nuts are usually seized on the bolts, causing the bolts to turn in the bed.  And then things get "fun".

I don't remember what truck you have (hint: put info in a signature) but the basic ones have two lines - the fuel hose and the vent hose which goes to the charcoal canister under the battery.  But some have a return line as well.

If you can get the tank low enough to reach in there you can pull the hoses.  However, you may find that the hoses are sticky, gooey messes.  They were designed for the ethanol we have in the gas now, and it really messes them up.

I guess I will share my dreadful method. I hate dropping an old tank. mostly because i cannot stand the smell of gas on me.  I start by disconnecting the fill tube. remove gas cap etc. remove the fill tube from the box and the bed and the fill hose. there is a corrugated inner vent tube slide it out of the steel fill tube as well.                                          
remove the spare tire hanger j bolt and swing the hanger as far away under the axle as possible.
then I put a ratchet strap under the tank and remove the braces. leave the top straps alone.
 then I crawl under and hold up the tank and remove the strap and lower the passenger side down, and this often means holding the tank against the driver side as the flange around the tank seems wider than the frame opening. with it hanging at an angle resting on a jack, box, milk crate or whatever. just not hanging by the fuel line. now you can reach in from the passenger side and disconnect. unplug the wiring and inspect the connection hoses first. if they are in poor shape just cut them with snips as you should replace anyway. then it's just the matter of getting the fill tube over the frame.  

IowaTom wrote

Matt - As sure as I can be on the direction of flow, from an arrow on the side.  I'll try to run the engine with an alternate fuel source... figure something out.  Just thinking the tank needs to come down if I'm ever going to drive this truck without a dry mouth.  :-)

I ran my truck for a few years off a gallon jug on the inner fender as I was rebuilding as I did not want gas sitting in the tanks that could of been years.

Only thing I can tell you make sure you are using the right size fuel hose.
I could not pull fuel from the can and thinking the fuel pump dried up and stop working so I replace the pump. New pump also would not pull fuel so I put a 2nd clamp on the hose at the pump, still not pulling fuel.

I was using 3/8" hose, switching to 5/16" hose it then pulled fuel and yes I have a 300 six in my truck.
Dave ----