WHEN YOU THROW open your shed doors to wake up a classic thatís been languishing for a lengthy period, donít be surprised if the car displays less enthusiasm for the start-up plan than you. Machinery hates to lie unused for long periods. Achieving success on the first start-up is therefore likely to require a bit of extra effort on your part.
This guide covers the basics of starting a laid-up car and explains what to do if it fails to play ball. It should also come in handy if your car suddenly decides not to start in any situation throughout the year.
The basic principles of an internal combustion engine are pretty simple. A cylinder will fire if it has fuel, a spark delivered at the right time and compression. If it doesnít fire, you just need to identify which of these ingredients is missing, then work out why itís missing.
Weíre assuming the engine turns over in the first place. If turning the key brings a feeble click or a deathly silence, check the battery condition, the leads and connections to the battery and starter, and all major earth connections. Tap the starter smartly with a heavy hammer to jolt stuck carbon brushes into action.
Remember to give the car a thorough once-over before roaring triumphantly onto the street. At the very least, check all fluid levels, make sure all the lights work, carefully inspect the braking system and check the tyre pressures. Undertake a couple of short trips first, keeping your eyes and ears open for anything peculiar.
If everythingís dripping with condensation, dry the coil, HT leads and distributor cap before you start.
Start by looking for loose wires, crusty-looking connection, decaying fuel hoses, coolant leaks, nesting rodents and anything else thatís obviously not as it should be.
Test lamp or multimeter, feeler gauges, jar, spare condenser.
If the car hasnít moved for over a year, drain the tank and add at least five litres of fresh fuel. Fit a new in-line filter to catch any rusty shrapnel from the tank.
A failing battery may crank the engine, but the voltage may be too low for sufficiently strong sparks to be generated.
1. CHARGE BATTERY If the battery hasnít been touched since the car was parked, give it 12 to 24 hours until the cells are all gassing enthusiastically. Alternatively, let a smart charger take care of it.
2. CLEAN TERMINALS Clean the battery terminals and clamps with abrasive paper. Fit them tightly with a smear of petroleum jelly.
3. CHECK FLUIDS Check the coolant level in the radiator. Top it up if necessary with 30% mix of antifreeze and water. Check all other fluids, too.
4. CHECK FOR SPARK Turn the engine so that the points are closed. Switch on the ignition. Flick the points with an insulated object (eg, wood or plastic) until a small spark is seen at the contacts with each flick.
5. PRIME OIL AND FUEL Put gearbox in neutral Donít depress clutch or operate choke or throttle. Turn the starter for 10 seconds. Wait 30 seconds and repeat. This should prime the petrol and oil pumps.
6. START IT UP Let it crank until the oil pressure lamp goes out, then pull the choke and let the engine fire up. Donít rev the engine while itís cold.
7. PUSH IN CHOKE Push the choke in as soon as the engine will hold a steady idle.
8. CHECK COOLING Let the engine warm up. Make sure the top and bottom radiator hoses are the same temperature, indicating that the thermostat has opened. Check that the electric fan (if fitted) cuts in at a sensible temperature.
Youíll need to be systematic, rather than poking randomly at things. Your plan of action is: fuel, sparks, spark timing, valves. Work your way through the steps on the following pages in the order suggested and you should be on the road in no time.
ĎFuel should be okay for a few months. But was the tank almost empty when you put the car away? The dregs may have evaporated to below the level of the fuel pick-up.í
SMELL PETROL? Remove the air filter lid. Can you smell petrol? If not, perhaps no fuel is reaching the carburettor. Start by making sure the chokeís working. Check the cable to the choke flap, jet or valve, as appropriate.
DELIVERY ISSUES Remove the fuel hose from the carburettor. Is there fuel in it? If not, direct it into a jar and crank the engine. It may take a while for the pump to prime. If this fails, check the tank, pump and any filters.
VALVES AND NEEDLES Fuel pump failure is likely to be due to dried out or sticking valves. Strip, clean and reassemble, if possible. If itís OK, remove the carburettor top and make sure the needle valve isnít obstructed or stuck.
Blowing through the pump in the direction of fuelflow might free stuck valves.
SPARK PLUGS If the fuel system is okay, the next suspect is the ignition system. Take out the spark plugs. Let them dry if theyíre wet with fuel. Clean them with a brass wire brush and set the gaps (usually 0.6mm)
DISTRIBUTOR Turn the engine so the points are closed. Flick them open repeatedly with the ignition on. If they donít spark, hold them open and check theyíre getting power. If they are, try another condenser.
SPARK AT COIL? Replace the distributor cap and remove the central HT lead. Hold it in insulated pliers about 5mm from the cylinderhead and crank the engine. A strong spark suggests the points and coil are fine.
SPARK AT PLUGS? Replace the HT lead. Attach one of the spark plug leads to a spare plug and rest it on the cylinderhead. Crank again. If thereís no spark, the rotor arm or its contact in the cap are defective.
LOW TENSION PROBLEMS The most common problem is oxidation of the contact surfaces of the points, which prevents current flowing through the coil. Flicking the points or a rub with fine wet-and-dry paper should fix this.
Clean off any dust after using abrasive paper on the points.
HIGH TENSION PROBLEMS The usual obstacle to sparking at the plugs is dirt on the coil, HT leads and distributor cap. Clean inside-and-out with petroldampened rags. Replace any protective rubber caps that have split.
HT LEAD ORDER If fuelís going in and the plugs are sparking, check the sparks are arriving in the right place at the right time. First, make sure Santaís helpers havenít replaced the HT leads in the wrong order.
SET TIMING Align the timing marks on the crank pulley (check a manual if theyíre not obvious). Take off the distributor cap. The points should be just opening. If not, turn the distributor body until they are.
POINTS GAP Check the points gap while youíre there. When the points are held wide open by the heel of the cam, make sure thereís a gap of 0.4mm between the contacts. Put a dab of grease on the cam, too.
Retime the ignition after adjusting the points.
VALVE TIMING TROUBLES? With fuel and sparks arriving in the right place and on cue, the only thing left to check is the valves. Start by checking the valve timing if the engine is overhead cam and has a timing belt. Remove the belt cover and turn the engine so the timing marks of the camshaft pulley(s) line up. Now look at the timing marks on the crankshaft pulley. The TDC mark should be lined up exactly. If it isnít, the timing belt has jumped.
BELT TIMING If the belt has jumped, find out why (wrong belt tooth profile, failed tensioner, seized water pump or idler). Replace the belt. Check the idler and fit a new one if itís anything less than perfect.
Beware: Timing belt catalogues sometimes list the wrong tooth profiles.
CHAIN DRIVE? Such mayhem is less likely on a chain-driven OHC or OHV engine, but itís worth checking. Turn the engine until cylinder one is at TDC and the rotor arm points to the cylinder one segment of the cap.
CHECK CAM POSITION Both valves of cylinder one should be on the back of the cam, with some clearance between the rockers and valves. You can also check the cam pulley timing marks on a chain-driven OHC engine.
CHECK CLEARANCES If the timingís OK, check the valve clearances. If thereís no clearance and the valves canít shut, the engine will struggle to start when itís stone cold. A telltale is a suspiciously fast cranking speed.
ĎSniffing the exhaust tailpipe after cranking the engine is a good indicator of whether fuel is getting into the cylinders.í
BASIC CHECKS If electronic ignition is lifeless, first check all multiplugs for corrosion. See if a sparkís generated as the ignitionís turned on or off. This shows the coilís fine, but doesnít necessarily OK the amplifier.
TEST AMPLIFIER Remove the plug from the distributor. If it has three pins, repeatedly connect the middle pin (sensor output) to one of the outer pins (supply). If this generates sparks, the amplifierís working.
Connecting the sensor output to the Ďnegativeí sensor supply wire usually produces a spark.
CHECK WIRING If the coil and amplifier are working, this implicates the sensor in the distributor, or broken or corroded wiring. Test for continuity between ends of all wires before condemning electronic components.
FURRY CONTACTS SU-type pumps that tick have contact breakers under their base cap. These can oxidise over lengthy idle periods. Clean them with fine wet-and-dry paper. Make sure the mechanismís free to move, too.
STUCK VALVES Just like manual pumps, electric pumps have diaphragms and valves. Diaphragms can become porous or split and valves can stick. Solid disc valves can be prodded free. Be gentle with rubber valves.
INJECTION PUMPS If your pump is a high-pressure rotary type, first check the fuses and relay. Bridge the relay terminals to test. If that fails, try a direct 12V supply to the pump. It may be seized or electrically Ďdeadí.
PETROL INJECTION Make sure the fuel pump runs for a few seconds after the ignition is turned on. Crank and check for a spark at the plugs. Check all injector plugs are firmly connected and rust-free. Check wiring.
DIAGNOSTIC SYSTEMS If the car has an OBD diagnostic system, find out what it thinks is wrong. Bear in mind that a Ďfaulty senderí, or similar, is far more likely to be a faulty connection after a period of standing idle.
DIESEL WOES Glow plugs should be warm to the touch after operating. Check the circuit/relay if they all stay cold. Injection can be foxed by a blocked filter, cold and waxy diesel, or gums and resins from cooking oil.