Old Faithful -- Not Now, Won't Start

[Stocker]

Truck drove OK a couple weeks ago. Had to crank a lot to start it but that's been happening after sitting several days. Once it fires up it's been running fine.

Tried to start yesterday, no go. Cranked strong but wouldn't catch unless I gave it a shot of starting fluid. Then it fired momentarily, then died. Okay, no gas....

Looked at it this morning, tanks are not full but seem to have more than enough. Disco'd the hard line at the carb, dry as expected, hooked up the pressure gauge and hit the key. Jumps up to ~6 psi, should be good, but still no fuel.

With good pressure, I'm assuming the fuel pump works. Is it possible to build pressure without pumping fuel? I replaced the under-cab filter recently and have driven the truck since then, so it should be good. All my tanks are locked and I see no sign of forced entry, and the gauge shows fuel and I also staked two of the tanks. Pretty sure there's enough gas, just not getting any to the carb.

Now I'm stumped. What am I missing here? Thanks for any help....

[Coley]

So you have an original series engine correct?.....and you are using an electric fuel pump correct?
Where is your fuel pump located? Sounds like you need to check your fuel output right at the fuel pump using a spare gas container or equivalent.
If you have fuel leaving the fuel pump then you have a problem somewhere in the line between the fuel pump and the carb.
All good
Coley

[davepl]

How are you starting it? These aren't EFI and I presume you've lived with a carb before? Ignore me if this gets pedantic, but just to be safe:

If it's cold and been a while:

Crank the engine for 5 seconds or so to fill the fuel bowl on the carb
Pump the accelerator to the floor 2-3 times
Release, touch nothing, and crank

The first two steps, if missing, will prevent you from cold-starting. It needs the extra shots of fuel and the choke set.

This all presumes you HAVE the choke and choke coil and choke pull off can and choke pull off rod and all of that... otherwise it's "pump 10 times and crank and pump like mad" for a race engine :-)

If you're getting fuel up to the carb but none into the engine, maybe the accelerator pump diaphragm is shot?

[Stocker]

Thanks for the reply. I have checked a few things since posting.

It's all original, with a mechanical pump on the right side of the engine. Steel line from the pump to the carb is good. Disco'd the pump intake line and blew air through it, can hear bubbling inside the tank. Good.

Looking like a bad fuel pump. Next I'll run a hose from a gas can to the pump intake and see if anything comes out.

[Stocker]

Dave -- no problem, I've owned this truck for 39 years and it was my DD until I retired 7 years ago. Everything before that (back to the mid-Sixties) was carbureted also. It's just not getting any gas to the carb.

[davepl]

Thanks, you never know, but I've been meeting a lot of people lately that are just getting their first classics (in a long time, anyway) and who've forgotten about chokes and old steering boxes and drum brakes and... so on. Had to rule it out :-)

You said you had 6psi which makes me think the pump is OK... does it free-flow pump OK while cranking if you have the line stuck into a gas can or bottle (takes two people)?

[A1971Blazer]

bad fuel pump........
I helped a kid on the side of the road just up from the Co-op...he had a '67 c30 with a dump bed full of loose corn....
He had just installed a new (reman) fuel pump. I did all the things you mentioned even went so far as to pull the sending unit out of the tank(behind the seat)....turns out, the "new" pump was bad.

[Stocker]

Ran out to buy a section of hose for testing, stuck it in a can of gas and the pump worked flawlessly...

After all this head-scratching (and I really really hate to admit it) but I wonder if the gas thieves got past my locks and there was less fuel in the tanks than I thought. As in not enough to be picked up. Gauge is not as accurate as it used to be.

I'm off to fill my mower gas can. I'll let you know what happens.

Not a total waste, though, even if adding gas "magically" fixes it. Found an old brittle section of hose on the intake side of the pump so will replace that before it leaves me stranded.

[A1971Blazer]

cracked fuel line could cause it not to start and still not leak....the pump will suck in air through the cracked line and not allow it to draw in fuel....I had an old '79 F250 4x4 that did the same thing.....found cracked rubber fuel line at the tank....it didn't leak fuel just wouldn't pump it up to the carb.

[Coley]

....ba-da-bing....you are getting close to be good to go again by the sounds of it.
Always pays to test and thoroughly investigate because on these vehicles it is usually something much simpler than originally thought.

Keep us posted.
Coley

[Dave in Ozark]

Which carb do you have? I'm a relative newb but on a 69 I had there was a filter at the carb inlet just behind where the fuel like e entered. Maybe there? If you apply fuel pressure and it is t getting into carb next step, I believe would be filter, then float. Bowl dry?

[Stocker]

Dave -- Q-jet, and yes it has an inlet filter. Very first thing I did was disco the hard line at that connection, had no fuel from the line.

Blazer -- yup, and I checked every line I had access to. No go from either of the two tanks I tried, though.

Anyway, the truck runs like a clock now. It pains me to admit it, but it's funny what a couple gallons of gas will do for ya. No idea how much the dirty thieves got away with, but at least the tanks weren't full.

So I'm thinking the locking cap and the side Travel Tank doors probably have pretty common locks on them, or are relatively easy to pick. Keeps the honest folks honest but only slows down a decent gas thief for a minute or two. Only thing I can do now is leave the passenger side tank empty and park the wrong way, with the drivers side tight against my fence. Make it a bit tougher for them next time.

[special-K]

I have a really hard time fixing a truck too low on gas. No matter what i do it doesn't help. Finally, I get fed up and just put gas in it and drive on

It's ok, I've been there. Especially on this '72 GMC with three tanks, gauges not working, and forgetting which way the valve does what. It always runs fine when I switch to the tank with fuel...once I figure it out!

[garyd1961]

I've seen them come into the dealership on a rollback and the customer complains it wont start. After an hour of checking the mechanic figures out it's out of gas. I've also had more than one to run out of gas while I was changing the oil.

[special-K]

I bought my '85 diesel Jimmy about 5 miles from here and drove it home. The first time I moved it in the driveway, like 20', it stalled and wouldn't start. Out of fuel. What a cheap S.O.B. to let me drive off with maybe a quart of fuel. And the way I came to know this thing was for sale is I stopped to help the old man on the side of the road with his (Duramax) hood up and he told me about it

[Stocker]

Tim I can always count on your wisdom & support! Thanks buddy! The way these burn through fuel, I figured it wouldn't hurt to try to wean it. Not the first time I had to wipe egg off my face. Hope the gas robbers don't decide to make me one of their regular customers now.... I think that's the first time I've been hit.

So, to change the subject, got the new 3-point belts installed today.