Barn find 6.2 precautionary measures

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1977C20Silverado

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I’ve recently struck up a deal on an 82 c20 with the 6.2 and a sm465. Trucks got 120k miles, and hasn’t ran for 20 years. I wanna get it going again, but I’m just wondering what I should do before trying to start it. Imma change the fluids, clean injectors, flush out fuel lines, etc. Do yall got any input on things to do? I don’t got much experience with the Detroit’s, so this is pretty much all new to me. And does anyone have a good link or part number to an injector rebuild kit?
 

Rickf

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You might try removing the glow plugs (10mm deep socket) and try to turn it over first.
Don't be surprised If the plugs put up a fight coming out.
That will determine step two.
 
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backwoodsman

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Do you know, or can you find out, why it was left to sit 20 years ago? If there was some kind of problem, that would be the place to start. Otherwise, here's what I'd do:

I'd recommend leaving the injectors & lines alone unless you know there's a problem there.

Put batteries in it and bump the starter to make sure it's not froze up. Make sure the glow plugs are working, or at least can be fired manually by jumping 12v to the relay. For now, you don't need them all working, but hopefully at least half of them do.

There should be a port on top of the fuel tank where you can attach a hose to draw from the bottom of the tank; see what comes out when you suck on that. If fuel, you're good to go; if water, algae, or sludge, drop the tank and clean it out (or rig a temporary tank just for testing, and worry about the fuel tank later). Make sure you can pull fuel from the tank through the primary filter.

Change the oil & filter. Remove the 12v wire from the injection pump so it won't fire, and crank it enough to get oil pressure. Reconnect the 12v wire, fire the glow plugs, and see if it'll start.
 

vr1967

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My 84 k1500 6.2/4speed sat up for 9 years before I got it. I put 2 batteries in it, had it fired up in less than 2 minutes and drove it home.

I wouldn’t change anything until I knew it was worth messing with.
 

1977C20Silverado

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Sorry I should’ve included this, but I was told it had a motor knock. I’m figuring it’s an injector due to the relatively low miles. IDK how common it is for bad injectors to sound like knocks, but between it being the first thing that came up when I searched 6.2 knock, and for as cheap as the truck is, I couldn’t pass it up. But I’ll also be dropping the pan to inspect the bearings
 

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