You've found a truck (or maybe it's found you) ... In a barn or along a fence row. It looks complete. You ask yourself the big question ... "Will it run?" You want to run after your jumper cables and a can of ether ... Well hang on a moment there, Sparky! There's a few things you might want to do and check before you go about ...
Phil "TrknGMC" Pierce prepares to bring a long-dead GMC 302 back to life.
First things first!
It's natural to want to start up that newly found old truck. But before you put the voltage and ether to a dormant engine to start it, there are a few simple steps to take to ensure you don't inadvertantly cause damage to either the engine or yourself. There's usually a good reason why a truck was dragged to the woods or stuffed into a barn, and more often than not, that reason is something mechanical. So put the ether and jumper cables away for a moment and let's make sure the engine is ready.
Sure, you can just check the oil and put the jumper cables to it and redneck it - but why risk turning a potentially good engine into scrap metal? With just a few steps and a little investment in time, you can safely resurrect a dead engine and save yourself time and money.
Stage One -- Initial Check
BEFORE you sink money into batteries, plug wires, gas, etc., here's a few initial things to check to see if it's even worth trying to start the engine:
Check the engine over to ensure all necessary components are in place (carb, generator, fuel pump, water pump, oil pan, valve cover, etc.) and appear to be serviceable.
Pull the dipstick.
You should see oil (duh). Low is okay -- go ahead and top it off and proceed. You'll change it later (see below).
If you don't see oil -- determine if it's just low, or if there's a hole in the oil pan
If oil is milky / brown -- you have water contamination in the crankcase oil. This may be from condensation, from being out in the weather, or from that angry neighbor down the way who's always been jealous of your cool ride. Either way, it may mean the lower end was damaged. But if the engine is not seized, you may as well change the oil and proceed.
If oil has greenish brownish contamination -- you have coolant in the oil from a blown head gasket or a cracked head. You will need to pull the head to correct the issue before you can safely attempt a start.
If you have water on the dipstick -- bad! You are done. This engine is probably junk. At the very least, it will need a complete teardown and rebuild. DO NOT ATTEMPT TO START.
Check the radiator. Hopefully, you will see green fluid inside it. If brownish fluid or no fluid at all, proceed with caution and remember you won't be able to run the engine very long if you get it started -- no more than about a minute.
Try to turn the engine over by hand (to see if the engine is free or is seized). Some people are able to tension the fan belt with one hand, and pull the fan towards them with the other. Note: Wear gloves! Those radiator fins will take the hide off your knuckles! If you don't have a hand crank, remove the bottom cover from the flywheel and use a pry bar on the flywheel teeth to lever the engine around. If it turns at all, in any direction, it's not locked up. Yay! Either way, proceed. If it's seized, but passed the oil test above, pull all spark plugs, and examine them for obvious issues (i.e., if one is completely oil-soaked or fouled) If nothing jumps out, clean 'em up and set them aside. Put a few squirts of (pick one): engine oil; Marvel Mystery Oil; engine tune up treatment; or automatic transmission fluid in each cylinder. Loosely replace the cleaned plugs. You will need to let the engine sit for a few days or until you can get it to turn. If the engine won't turn after a month of soaking, it will need to be disassembled and rebuilt.
Stage Two -- The Pre-Start Check List
Helpful Hint - Top Dead Center
While you have the plugs out and the valve cover off, take a few minutes and put the engine at Top Dead Center on No. 1 cylinder! When the piston is all the way at the top with both valves closed (and confirmed by the timing mark on the harmonic balancer) -- TDC!
Engine Pre-lube. Start at the top! Pull the top valve cover off and check for obvious problems with the rocker arms and push rods. If nothing jumps out, liberally squirt engine oil over the rockers and valve stems. (Once the engine starts, it takes a minute or two for oil to get up top). If you haven't already put some lube oil or penetrating oil in the cylinders (through the spark plug hole), do so now. Lastly (for this step), check the engine oil and fill / replace as necessary. At this point, the engine should turn over by hand smoothly and fairly easily with no grinding, catching or wobbling. Leave the valve cover off and the plugs out for now.
If you're going to index the distributor and set the timing (see below), this could be a good opportunity to pressurize the lubrication system. Pull the distributor and using an old long flathead screw driver (with the handle removed so it fits into a cordless drill), spin the oil pump. You'll know when you have good oil pressure -- it's when the drill suddenly snaps out of your hand from the sudden torque.
Pop the distributor cap and check for fouled / missing points. Hit 'em real quick with a points file. Check the rotor and cap for carbon build-up, clean as necessary. Put a drop of oil on the distributor cam while you're at it. Replace any part that looks too bad to be cleaned or filed. Note that it IS indexed (see note at right). Rotate the engine -- Does the rotor turn? If not, do not proceed until you know why not and have corrected the issue.
BTW, how do the plug wires feel? Are they brittle and stiff, and crackle when you flex them? If so, you're probably headed for a new set. If the local parts store doesn't carry your specific set, use a universal six-cylinder set, but get the older style, solid-core wires.
Next, we'll turn our attention to the battery cables. Let's start with ensuring you have the correct voltage battery! Next, check the ground strap. Usually, it helps just to loosen / retighten the bolt and nut attaching it to the frame, but if it looks corroded, then remove it completely and clean the connections to clean, bare metal and reattach. Do the same for the positive cable, cleaning both ends with a terminal brush and / or sand paper. Install a fully charged battery and make sure the ignition switch is "off" before you attach the cables to it.
Install a known good coil (with the correct voltage for your truck).
Electrical System Check. With the battery connected, and a multi-meter in hand, turn the key to "on." Check under dash and in the engine bay for anything hot, smoking or sparking. If no indications of issues, use the multimeter to check power at the starter (where the battery cable attaches. It should read 6 or 12 volts (whatever you truck is wired for). Now check to see if you have the same voltage on the coil and at the distributor (the wire running from the coil to the outside of the distributor). Everything good? Turn key back to "off" to secure the electrical system for now.
As you have both the valve cover and the distributor cap off, and the plugs out, why not set the points and timing? With the engine at TDC (Top Dead Center - see green square above), the rotor should be pointing at the No. 1 cylinder. Rotate the engine backwards to put the timing mark on the harmonic balancer under the indicator (the engine is at the firing point for #1 Cylinder). Index ("turn") the distributor until the points are just opening and the plug wire for the #1 cylinder on the distributor cap is over the rotor. If you have power available to the electrical system, you can check if the points open and spark as the engine rotates through the timing mark. If not, adjust the distributor until it does. This should get you nearly perfect timing, or at least good enough to start the engine. You can fine tune it after the engine is warmed up. This will also work for an 8-cylinder engine. Just make sure you know which one is the #1 cylinder.
Put the spark plugs, valve cover and distributor cap back in place.
Fuel System. It's not safe to assume the truck's fuel system is safe to use after prolonged sitting. The diaphram in the fuel pump is likely to be dried out and brittle, and the fuel tank will likely have sediment and other contaminants in it. If all we're after is just getting the engine to run, we can rig a temporary fuel supply (and save the fuel system rebuild for later). A small outboard motor gas tank with a bulb primer in the fuel line will work nicely. Just disconnect the existing fuel line (from the fuel pump) at the carburetor and install a hose barb. Another option is a hand-held yard sprayer. Just make sure you don't over pressurize the system and blow by the needle valve in the carburetor. Connect the fuel line from the temporary fuel tank, secure the fuel tank somewhere higher than the carb (on the fender, for example) to gravity feed into the carb. Squirt some penetrating oil on the throttle and choke linkages.
At this point, pause to check everything:
Fuel supply system?
Stage Three -- Engine Start
Roger Houston, we are go for launch! With everything ready per the steps above, and with your fire extinguisher handy, it's showtime!
Pump once or twice on the pedal, pull the choke, turn the ignition switch to "on" and give her a go!
Once it fires, don't over-rev the engine. Just run it fast enough to keep it going until it's warmed up. Adjust the choke as necessary to keep it running smoothly.
Resist your urge to put it in gear and go for a ride -- even to move it a little just in the shop. Unless you've checked out the driveline, many issues could exist to cause problems. It sure would stink to have it get stuck in gear with a locked up clutch ... and no brakes. Let's work one system at a time and today, it's the engine. Save the drive line and brakes for later, once you know the engine runs.
Once you've let it run 10 -15 minutes, shut it off -- That's enough for now.
Drain the oil immediately (while everything is still hot all stirred up) and put in fresh. Drain the coolant and put in fresh. Then run her some more. Other issues will crop up, to be sure. But once it's running, it's a lot easier to stay motivated. And you'll need motivation to redo the brakes ...
Congratulations! You have successfully brought a dead Stovebolt back to life! Now fix those brakes!
When all else fails, just ask yourself, "What would the honey badger do?"