Looking for tips on what else to do to give my truck the best chance of starting after fuel tank replacement.

[dkraven]

The truck technically runs, I drove it around the block from the neighbor who gave it to me last fall, but it kept stalling due to a clogged fuel line. Aside from that issue it's generally been well maintained, though with long periods of sitting. I'm finally getting around to replacing one of the fuel tanks and its sending unit (saving the second tank for later) and when I go to fire it up I want to have the best chance at success. I'm handy and methodical and have done basic vehicle maintenance stuff, but this is a bigger project for me, so any advice from more experienced people would be appreciated.

Once I get the tank installed and fuel line and electrical hooked up to the sending unit, what do you all suggest to get the cleanest start? Obviously I need to put gas in it. I'm not sure if I should bother changing the oil before making sure it starts and runs, but I'm considering doing that. The guy who gave it to me sprayed starter gas of some kind in the carb when we started it, but not sure if I should bother doing that. Any other checks I should perform or tips you all have, I'm all ears.

It should say in my profile, but it's a 77 GMC Sierra Grande with a 350 engine, automatic transmission.

 

[Radiohead]

Mainly after you have the repair finished, once you get it running be sure to go over the lines and hoses with an eye for leaks.
If you put some gas down the carb before you try to dry start it, you will have a better chance of it getting some fuel drawn up into the float bowl. You can use starting fluid too, until the carb fills and takes off on its own.

 

[75gmck25]

Probably replace the passenger side tank first, since I think that is still the main tank on a ‘77. The older one-terminal fuel switching solenoid under the truck is designed to default to the main tank when it has no power. Using only the main tank makes it work like a single tank truck, and takes the switch and solenoid out of the troubleshooting process.

 

[rusted nuts]

The truck technically runs, I drove it around the block from the neighbor who gave it to me last fall, but it kept stalling due to a clogged fuel line. Aside from that issue it's generally been well maintained, though with long periods of sitting. I'm finally getting around to replacing one of the fuel tanks and its sending unit (saving the second tank for later) and when I go to fire it up I want to have the best chance at success. I'm handy and methodical and have done basic vehicle maintenance stuff, but this is a bigger project for me, so any advice from more experienced people would be appreciated.

Once I get the tank installed and fuel line and electrical hooked up to the sending unit, what do you all suggest to get the cleanest start? Obviously I need to put gas in it. I'm not sure if I should bother changing the oil before making sure it starts and runs, but I'm considering doing that. The guy who gave it to me sprayed starter gas of some kind in the carb when we started it, but not sure if I should bother doing that. Any other checks I should perform or tips you all have, I'm all ears.

It should say in my profile, but it's a 77 GMC Sierra Grande with a 350 engine, automatic transmission.

Make sure tank is bad, And/or fuel lines are pluged.

 

[SquareRoot]

Make sure tank is bad, And/or fuel lines are pluged.

Hmmmm....interesting.

 

[fast 99]

Use a small plastic bottle with a small nipple on it. Fill the carb through the bowl vent holes.

 

[Snoots]

While you have the tank out, disconnect the line at the fuel pump and blow out the line(s). Change out ALL fuel filters. Check ALL rubber lines for cracks/leaks or, replace them with SAE spec J30R10 hose. Better to replace now than have to deal with them later. Clean ALL electrical connections at the tank(s).
If you are changing out the tank pickup, replace the gasket and if possible the pickup 'sock'.
Get all that out of the way and never worry about it again.

 

[SirRobyn0]

I know you asked about starting, but I'm going to add this. Replace the sock in the fuel tank. There is a "sock" style filter at the end of the pick up tube in the tank. If it clogged from time, or bad gas sitting in it, it will never get fuel through.

As far as starting the truck, putting gas in the carb, either pre-filling the float bowl or just down the throat will help get a quick start, but if all the lines are clear, the filter is clean and the pump is healthy it should be able to fire with just a bit of cranking.

 

[WP29P4A]

I'm guessing with replacing the tank, sending unit and fuel lines, you also replaced the fuel filter? (I didn't see it mentioned) When I have to work on the fuel system, I change the fuel filter and pull the fuel line from the carb to run fuel through the new parts to rinse any particles out of the system before connecting it back up to the carb.

 

[Grit dog]

If it doesn’t start after a few seconds of cranking. Pour a little gas down the throat and light er off…there’s really no other considerations to re start it so if it’s all working it will start on its own or worst case with a shot of gas to get the engine to light off and run the fuel pump fast.

 

[Scott91370]

Without the fuel poured into the carb you're going to crank a while - and it will probably take a couple of tries doing this. Until the fuel gets all the way from the tank and fills the bowl(s) that pump is going to be trying like mad. At least with pouring fuel into the carb it'll run a bit and not heat soak the starter and drain the battery.

 

[codfish]

If you had an electric fuel pump kicking around, hook it up to pull fresh gas thru the lines before connecting to the carb. Maybe overkill but simple enough if you have one. If you prime it thru the carb before firing it off, consider a little 2 stroke oil in the gas you prime it with. Helps lubricate the cylinders before it dies up.

You mentioned oil change. Get it running and warmed up before changing the oil. Warm/hot oil will help carry any sludge from the top end of the engine to the base pan where you want it when changing the oil.

Good luck

 

[Ricko1966]

I just do it like @fast 99 Fill the float bowls through the vent tube using a cleaned and dried dish soap bottle the little hole in the cap is perfect. Those bottles are also good to keep diesel in for starting dead diesels or cleaning parts.