Gas tank vent...maybe

[mtruckr]

On a '66 Suburban... quit running, but will run on starter fluid.
Maybe a fuel pump failed... put in another one that I would bet money was good (famous last words), no luck.

Old skool assistant says pump prob doesnt work (no ability to generate suction with thumb covering intake pipe)... and a new one for $22 ain't no big deal...

However, tried to add fuel to tank (it was kinda low and mightve been part of the problem, but I doubt it)... and found that fuel was hesitant to go down the filler neck. (was NOT using a long funnel or gas nozzle... was spoon-feeding it from small available gascans and water jugs).

So the question is... anybody ever has a vent hose get blocked and generate these same issues?

I don't figure 47 year old rubber hoses last forever, and I don't imagine it would be too tough to find/remove/replace... but just like to get input before diving in.

Thanks for ideas and experiences
Kelly O.
Alpharetta GA
rusty 66 Suburban - 305V6

[ChuckW]

So.... When you replaced the pump, did you get any fuel out of the inlet hose to the pump? I really don't remember these old trucks having a "vent" line. I thought they vented through the cap in those days???
If you know you have fuel in the tank and nothing at the FP inlet you've most likely got a clog in the line somewhere.
I know this does not answer your question on your filling issue, but I'd start at the tank for your problem.... Good luck

[mtruckr]

did not check, of course ...

But just talked to some folk for a couple ideas to eliminate possible sources of trouble. And your idea of seeing what might flow through from inlet to outlet after turning it over was one of them...

Also, a 5 gallon can of gas and a real funnel will help me doublecheck on the gas fill-up issue.

Details soon...

[mtruckr]

What seems to be the case...

The original fuel pump doesn't move at all when the intake side is stopped up.
The second pump installed moves and acts like nothing is blocked...until you block the weep hole.

So I believe the first pump is actually okay, and the replacement one is sadly useless.

What I BELIEVE was the trouble spot was actually the fuel filter... trying to blow through it was quite difficult. The contrast with the new one was significant.

Regardless, I had ordered a new fuel pump, so I will install it... one less thing to think about for 5 years, let's hope. Also will install a new clear fuel filter and see if the beast comes back to life.

I added more gasoline using a full-sized funnel... no apparent hassles adding fuel, so I've taken 'vent hose' off the list of potential troubles for now.

Any other ideas, please contribute...

[bedfordia]

I had a similar problem with my 63. Turned out to be that the inlet hose to the fuel pump was a little too long and had a bit of a loop in it. when the fuel pump put suction on the line it would kink and shut off flow. 'Bout drove me crazy!

[mtruckr]

So the new fuel pump was installed... as well as the new (see-through) fuel filter. Engine cranked right up, so I'm happy with the outcome despite not REALLY knowing which item caused the problem.

But of course, now the outlet tube leaks at the pump connection, so that will require some attention. Both of my sources say NOT to use thread tape on those threads. It's remotely possible that the pipe may now have a split in it or some such... regardless, it leaked easily even after close attention was paid to the tightening of it. SIGH... it's always the last 5% of the project

And I DO believe I'm already seeing little brown specks on the new bright yellow filter material...

Thanks for the input here.

[1963c-10]

Might be worth dropping the tank and cleaning out the entire fuel system. You'd hate for a fuel gremlin to catch you at a bad time.

[mtruckr]

Okay... all seems well. Problem figured out and remediated...

"Old style" compression fittings seem to involve just splaying out the tube and nuzzling it up against the conical receiver.

More recent style seems to involve folding over the splayed out tube and making almost a 2-layer ending... which bottoms out easily on an old-style conical receiver (or at least... THIS one did)

Rummaging around in those old peanut cans in the garage produced a new style tube to go with the new-style cone that was on the pump...

No leaks, runs smooth... :goodjob:

[mtruckr]

Just a few days later....

I'm offering a warning that some of you are already aware of:
These machines are talking to each other.

I know this because not 7 days after I replace a fuel pump on the '66 Suburban... the same part on the same style engine (now in a '69 c20) seems to have also gone bad

Let's hope I can use all I learned on Project #1.
Usually these events are so far apart in time that you forget what you did 'last time this happened.'