How to: Start an Engine That's Been Sitting (The Basics)

How to Start an Engine That's Been Sitting

Most of us will need to know how to start an engine that has sat for a while...
Many of you will get a Van or an engine that hasn't been run in a long time. Some of you simply have an engine that hasn't run for years.
Most of the time you have heard "It's supposedly rebuilt," or "It was running great when we parked it..."
Well, you really don't know what you have till you either run it or tear it down.

So, let's see if we can get it running!

First, pull the plugs. How do they look?
If the insulators all look kind of tan and in good shape, things are looking good.
If there is lots of black goop or lots of crud all over them, it's probably an indication of either bad maintenance or it could be burning oil.
Squirt some oil or Marvel Mystery Oil into the cylinders. A few tablespoons apiece should do it. A small piece of tubing stuck on the end of a small funnel works well. Let it soak while you work on a few other things.
Now check the carb. It's great if you have a good clean one you can switch out for the old one but that's not always possible. What you don't want to happen is suck nasty stuff from the bowl through the carb.
If it's been setting a looooong time, it's usually best just to rebuild it. Especially if the air cleaner hasn't been on it. If all the gaskets are dried out and split it may end up acting like a sprinkler!

This is a good time to remind you: Always have a fire extinguisher handy...

If the carburetor hasn't been setting too long it might be ok. If it doesn't look too bad, then try it. It's best if you can pull the airhorn assembly off to see in the bowl, but you run the risk of tearing the gasket.
If the fuel in the carb smells like varnish, the rest of the fuel system is also gunked up. If this is the case or you are starting up an engine out of the car, you need to rig up a little fuel system of your own. Use a small gas can and a hose and hook it up to the fuel pump on the engine. Be sure and tie it out of the way of the engine or anything that could hit it or spark near it.
If the air cleaner hasn't been on it or if there are a lot of open holes, stuff may have gotten in it. Pull the carb and look down into the intake. If you see anything, pull the intake off and clean it out and look down into the intake ports of the heads.

Now put all that stuff back together. Leave the plugs out though.
Now let's change the oil and filter. When you have the drain plug out, stick a finger, screwdriver, stick, etc. up in the hole and see if there's a big layer of goop in the pan. If there is, you may want to clean the pan out first, as you don't want to plug the oil pump and run the engine dry.
It's time to see if the motor will turn over. First take the distributor cap off so you can see the rotor. Now take a breaker bar and socket and get on the crank bolt and see if you can turn the motor over by hand.
Watch the rotor. If it turns with the motor, that's good. If it lags behind a little bit when you turn the motor, the timing chain may be worn out which indicates lots of miles.

You're just seeing if the motor is stuck. Don't turn it over and over, just a complete revolution. Now put some more oil in the cylinders. Turn it again. Did the motor seem to turn over smoothly? You might feel some resistance, but what you are looking for is something stuck or binding.
Now the cylinders should be lubed up. Turn the motor one more time pushing the excess oil out.
Put the plugs back in. If the old ones couldn't be cleaned, put in new ones.
Now let's check the ignition. Are the spark plug wires ok? Look in the distributor cap. Clean any corrosion from the terminals on the cap and also clean the rotor. If you have points, make sure they open and close, the gap is close and the contact points are clean. Replace the condenser. They are cheap and they are the culprit allot of the time for engines not starting that have been setting awhile. If the coil is suspect, then replace it with a good one or get a new one.

Now I've mention something on pre-lubing. That is, manually turning the oil pump to push oil through the engine like it would if it were running.
This is one of the biggest savers of engines if your engine is capable of doing it. A few oil pumps operate differently, and doing it is not practical. Most engine oil pumps however can be operated with a tool or old modified distributor. You can usually buy the tool for cheap at auto parts stores, catalogs, etc. You can also modify an old distributor that fits your engine. Grind the teeth off the gear or remove it and remove the stuff on the top leaving the shaft sticking out enough to get a drill on.
Use a big drill, preferably half inch. You don't have to spin it fast. You have to spin it in the same direction the distributor spins. Do it until you see oil pressure on the gauge. If you don't have a gauge, pull the rocker cover(s) and spin the pump till you see it come out by the rockers.
Some people will spin the drill some, turn the engine over 90 degrees by hand, spin some more, turn the engine again, spin, turn, etc. until the engine has turned over twice.
Now the engine is ready to be spun over with the starter.
If you can't pre-lube, then turn the motor over with the starter (without pumping the gas) until the oil pressure comes up.

"You're not trying to start it yet. Don't use starter fluid or pour gas down the carb. That's very hard on engines and can tear the motor up before you even get it started."

If there is fuel in the carb bowl, it should start and run long enough to pull fuel through the system. If there isn't, you can get fuel into it through the vents. Just use an eyedropper and squirt the fuel down the vent filling the bowl. Usually about a few teaspoons worth.

Quick overview...
-Oil down cylinders and make sure it turns over by hand.
-Change fluids and hoses.
-Make sure carburetor and fuel system is good to go.
-Make sure ignition is in good shape.
-Pre-lube if possible.

Now fire it up!
Listen for any noises that shouldn't be there. If there is, shut it down and find out what it is.
The engine may smoke for a while. This is normal.

Conclusion
Some engines will start right up and be perfect after not being started for 25 years and setting outside in a puddle. Some engines may blow up after starting them that have sat for 2 years in nice dry storage. It's kind of a roll of the dice. There are so many variables and little things that can go wrong when you start an engine. Hopefully this article will help eliminate some of those and make your engine start up successful!

Dan

A few editing suggestions.

Before connecting your good, fully charged battery, inspect the wiring, especially the battery cables. Repair or replace as needed. Electrical fires are difficult to put out, so don't start one!
Connect the battery and watch for a while. Nothing should smoke or get hot with the key off. Next, turn the key on. Again, check for signs of problems. The coil can get hot, so don't wait too long here.

When prelubing, the distributor is removed. BEFORE doing this, note the location of the dist. body and the rotor when the crank timing marks are at TDC. When installing, put the crank at TDC, then install the dist so the body and the rotor are in the same position. It may be 180 out, so if it backfires and will not start, rotate it 180 and try again before dead-timing. Also note that any dist. with a curved gear in it will spin the rotor slightly when removing and installing.
On a mopar slant six, the oil pump is directly driven by the cam. The only way to prelube is to crank the engine. Leave the spark plugs out when doing this.
On a Mopar small block, the cam has oiling holes that 'time' a pulse of oil to the valvetrain. It must be spun while prelubing to get oil to the valve train!
On early small block Chevys, the distributor body blocks off an oil passage. Using a prelubing tool without the body will not fill all the oil passages.
On a small block Ford, the hex that drives the oil pump may have a retaining clip at the bottom to hold it in place. It may not be there on a rebuilt engine. When prelubing, be very careful not to pull this out and drop it into the engine!


On any of our engines, the easy way to determine rotation for prelubing is to look at the vacuum advance. Place your hand with the palm at the vacuum hose end of the vacuum advance, with your hand following the advance, not jumping over a gap, wrapping your fingers around the dist. body. Your fingers 'point' in the correct direction. You can also watch the rotor when you spin the crank. ALL American engine crankshafts spin clockwise when looking at the front of the crank. When moving the crank in this direction, note rotor movement.

Mopar slant six and small block are clockwise.
Ford 240 and 300 6 is clockwise, 289 and early (non-HO) 302 is counterclockwise.
Chevy 6 and small block is clockwise.

great write up!

I'd also like to mention that it is a great idea to put a new fuel filter back at the gas tank and another by the carb before you start trying to pump fuel.

The 2 1/4" fuel filler line on my van actually rotted off the van and the inside of the line broke down into small ground pepper sized rubber specks. I ended up having to vat the tank and replace all the fuel lines, fuel pump, filters and rebuild the carb because those little rubber particles got into everything.

Only thing ill add -maybe has been covered?? is that after sitting for some years - Id definately put some diesel fuel in each cylinder - actually fill them up- let sit a day or two?? Then with spark plugs still out-try turning the crank over by hand!! This is all precautionary just to the cylinders possibly rusting due to the heating & cooling year after year- =condensation-- and if stored inside this will still happen. If engine turns over by hand - and doesnt bind - youre home free- if it does bind ?? fill again & wait a few days . The oil in the diesel fuel will actually lube the cyl walls up & will free any stuck rings. Ive even used a mix of diesel & auto trans fluid - just dont rush the process. Then if all well - just turn it over several times to clean out all the fuel & as others have mentioned - be cautious, look @ everything & try starting it. Happy vannin

I would suggest also that if the vehicle has sat for quite some time to put a fairly strong magnet on the fuel tank in the area of where the pickup collects the fuel (not where it comes out of the tank) if posible. On a lot of older rigs their is only a filter after the pump/before the carb, rust in the tank likes to eat fuel pumps.

I no I am considerably new to all this early van stuff and one thing that sticks in my mind are those 6 volt gauges that seem to be very hard to find. Should a person remove the hot wire that feeds power to gauges, ya no that 12 volt wire that hooks up to that reducer under the dash, before cranking that key. Do these reducers( sorry can't remember what it's real name is) go bad from sitting a long time? Just a thought I had, it might be irrelevant, but thought I would ask.

You can disconnect anything you feel unsure about.
The gauges aren't any more susceptible to damage than any other electrical component. You can check the connections before connecting power.
On the Dodges, the biggest concern for me would be the ammeter connections. Next would be inspecting for any added wiring, then the doghouse connections and harness due to vibration and heat damage.
Hopefully others can chime in on other makes.
To get an engine running, all you need are good battery cables, a way to trigger the starter (you can use a starter switch) and power to the coil (you can use a jumper wire). Everything else can be disconnected. You should look at the wiring diagram to figure out where to disconnect the main feed so you don't have to disconnect many connectors. Chevys use a big wire that attaches to the battery lug on the starter. Dodge uses a big wire on the starter relay.
Remember that if the plan is to get the vehicle back on the road, you want to check all the wiring anyway, so it might be better to do that before you start the engine. That way, you have gauges and an easy way to shut things off (key) rather than pulling a jumper wire if something happens.
If this is a donor vehicle and you are only concerned with the engine condition, you can skip that and just hot wire the bare essentials.

I know this isn't environmentally correct, yet when starting an oldie all the above is good--especially oiling up the cylinders. I, for a gallon or so running out of a jug, make a two stroke mix of about 50:1 which gets some oil right away to the valve train. Sure it smokes alot and might even foul some plugs but I know it takes a lot of friction out of that first, long, cold start. Also, the lighter oil you use for the sump the faster it gets upstairs to pump up the lifters. Hence, I use a really light oil for that first start and warm up. Then, I change the oil again while that light oil is still hot. Have even done this with transmission fluid which really cleans out and pumps up the lifters quickly. However, I wouldn't go down the road much with either.