Engine Trouble Service

Problem

Engine will not crank.

Cause

Run down battery. Starting circuit open. Starting motor jammed. Engine stuck up. Transmission not in nuetral or park.

Solution

Recharge or replace battery, jump start engine. Check dirty or loose connection, check starter safety switches. Remove starting motor and repair. Service engine. Move shift lever.

Problem

Engine cranks slowly but will not start.

Cause

Run down battery. Defective starting motor. Bad Connections in starting system.

Solution

Recharge or replace battery, jump start engine. Repair or replace starting motor. Repair, clean and tighten connections.

Problem

Engine cranks at normal speed but will not start.

Cause

Defective ignition system. Defective fuel system. Air leak into intake manifold. Engine defective. Plugged fuel filter. Restricted exhaust system.

Solution

Spark test, check ignition timing. Check fuel system components. Tighten connections or replace gasket. Check compression or leakage. Check or replace fuel filter. Clean or clear restricted exhaust system.

Problem

Engine sluggish, stumbles, lacks power, acceleration or high speed performance, hot or cold.

Cause

Defective ignition system. Defective fuel system. Restricted exhaust system. Loss of compression. Carbon build up in engine. Defective valve action. Thick engine oil. Wrong, bad or dirty fuel.

Solution

Check ignition system components. Check fuel system components. Check catalytic converter, muffler and tail pipe. Check or test compression.Service engine. Check tappet clearance, check cam lobe. Use specified engine oil. Change fuel or use recommended fuel.

Problem
Engine lacks power or high speed performance when hot only.

Cause
Engine overheats. Choke stuck. Manifold heat control valve stuck. Vapor lock.

Solution
Check cooling system. Free, repair or replace choke stuck. Free valve. Use different fuel or shield fuel line.

Ignition System

Problem

Engine cranks normally but fails to start.

Cause

No voltage to ignition system. Ignition module lead open, grounded, loose or corroded. Primary connections not tight. Ignition coil open or shorted. Defective reluctor or pick up coil. The ignition module is defective. Defective distributor cap or rotor. Faulty  fuel system. Engine faulty.

Solution

Check battery, ignition switch, wiring. Repair as needed. Clean, seat connectors. Test coil, replace if defective. Replace reluctor or pick up coil. Replace ignition module. Replace distributor cap or rotor. Check fuel system. Check engine and service if required.

Problem
Engine backfires but fails to start.

Cause
Incorrect timing. Moisture in distributor cap. Voltage leak across the cap. Secondary cables not connected in firing order. Cross firing between secondary cables.

Solution

Set timing. Dry the cap. Replace the cap. Reconnect secondary cables correctly. Replace defective cables.

Problem
Engine runs but misses.

Cause
Spark plugs fouled or faulty. Cap or rotor faulty. Secondary cables defective. Defective ignition coil. Bad connections. High voltage leaks. Advance mechanism defective. Defective fuel system. Mechanical engine problems.

Solution
Clean, regap or replace spark plugs. Replace cap or rotor. Replace secondary cables. Replace ignition coil. Clean or tighten bad connections. Check cap, rotor or secondary cables. Check, repair or replace advance mechanism. Check fuel system. Repair or service engine.

Problem
Engine overheats.

Cause
Late timing. Lack of coolant or other trouble in cooling system. Late valve timing or other.

Solution
Set ignition timing. Check camshaft timing, tappet clearance, adjust if needed.

Problem
Engine springs spark knock.

Cause
Incorrect timing. Wrong fuel used. Defective advance mechanism. Carbon build up in cylinders.

Solution
Set ignition timing. Use correct fuel as recommended. Repair or replace advance mechanism. Service engine.

Problem
Spark plug defective.

Cause
Cracked insulator. Carbon filled spark plug. Busted spark plug.

Solution
Set ignition timing. Clean spark plug. Install new spark plug.

Problem

Engine runs on or diesels.

Cause

Idle solenoid out of adjustment or fuel shut off faulty. Hot spots in combustion chamber. Engine overheating. Advance timing.

Solution

Adjust or replace solenoid. Service engine. Set ignition timing.

Starting System Service

Problem

No cranking and lights stay bright.

Cause

There is an open circuit in ignition switch. Open switch in starting motor. Open circuit in control circuit. Open fusible links.

Solution

Check switch contacts and connections. Check commutator, brushes and connections. Check solenoid, relay, switch and connections. Correct condition causing link to blow and replace link.

Problem

No cranking and lights dim heavily.

Cause

There is trouble in engine. The battery is low. Temperature is very low. Frozen armature bearings and short in starting motor.

Solution

Check engine to find the trouble. Check, recharge or change battery. Battery must fully charged with engine wiring circuit and starting motor in good condition. Repair starting motor.

Problem

No cranking and lights dim slightly.

Cause

Faulty or slipping drive. Excessive resistance or open circuit.

Solution

Replace parts of drive. Clean commutator, replace brushes, repair poor connections.

Problem

No cranking and lights go out.

Cause

Poor connection probably at battery.

Solution

Clean cable clamp and terminal and tighten clamp.

Problem

No cranking and no lights.

Cause

The battery is dead. Open circuit.

Solution

Recharge or replace the battery. Clean and tighten connections and replace wirings.

Problem

Engine cranks slowly but does not start.

Cause

The battery run down. The temperature is very low. Starting motor is defective. Undersized battery cables or battery. Mechanical trouble in engine.

Solution

Check, recharge or replace the battery. Battery must be fully charged. Engine, wiring circuit and starting motor must be in good condition. Test starting motor. Install cables or battery of adequate size and check engine.

Problem

Engine cranks at normal speed but does not start.

Cause

The ignition system is defection. The fuel system is defective. Air leaks in intake manifold or carburetor. The engine is defective.

Solution

Make spark test, check timing and check ignition system. Check fuel pump, line, carburetor or fuel injection system. Tighten mounting and replace gasket as needed. Check compression and valve timing.

Problem

Relay or solenoid chatters.

Cause

Hold in winding open. The battery is low. The contacts are burned.

Solution

Replace the solenoid. Charge the battery. Replace the burned contacts.

Problem

Pinion disengages slowly after starting.

Cause

Sticky solenoid plunger. Overrunning clutch sticks on armature shaft. Overrunning clutch defective. Shift lever return spring weak.

Solution

Clean and free the plunger. Clean armature shaft and clutch sleeve. Replace the clutch. Install a new spring.

Problem

Unusual noise.

Cause

High pitched whine during cranking before the engines fire. High pitched whine after engine fires as key is released. Loup whoop, buzzing or siren sound after engine fires but while starter engaged. Sounds like siren if engine is rewed. Rumble, growl or knock as starter is coating to a stop after engine starts.

Solution

There is too much clearance between pinion and ring gear. There is little clearance between pinion and ring gear. Defective overrunning clutch. Bent or unbalanced armature.

Injection Nozzle Service

Problem

Engine cranks normally but will not start.

Cause

Incorrect or dirty fuel. No fuel to nozzles or injection pump. Plugged fuel return line. Pump timing off. Inoperative glow plugs, incorrect starting procedure or internal engine problems.

Solution

Flush system and use correct fuel. Check return line clean. Retime pump timing.

Problem

Engine starts but stalls at idle.

Cause

Fuel low in tank. Incorrect or dirty fuel. Limited fuel to nozzles or injection pump. Restricted fuel return line. Idle incorrectly set. Pump timing off. Injection pump trouble. Internal engine problem.

Solution

Fill tank. Flush system and use correct fuel. Check for fuel to nozzles and to pump. Check return line clean. Reset idle. Retime pump timing. Install new pump.

Problem

Rougle idle, no abnormal noise or smoke.

Cause

Low idle incorrect. Injection line leaks. Restricted fuel return line. Nozzle trouble. Fuel supply pump problem. Uneven fuel distribution to nozzles. Incorrect or dirty fuel.

Solution

Adjust low idle. Fix leaks in injection line. Clear fuel return line. Check, repair or replace nozzle. Check, replace if necessary the fuel supply pump. Selective replace of nozzle until condition clears up. Flush system and use correct fuel.

Problem

Rough idle with abnormal noise and smoke.

Cause

Injection pump timing off. Nozzle trouble.

Solution

Retime injection pump timing. Check cylinders in sequence to find defective nozzle.

Problem

Idle is fine but misfires as throttle opens.

Cause

Plugged fuel filter. Injection pump timing off. Incorrect or dirty fuel.

Solution

Replace fuel filter. Retime injection pump timing. Flush system and use correct fuel.

Problem

Loss of power.

Cause

Incorrect or dirty fuel. Restricted fuel return line. Plugged fuel tank vent. Restricted fuel supply. Plugged fuel filter. Plugged nozzle. Internal engine problems or loss of compression and compression leaks.

Solution

Flush system and use correct fuel. Clear fuel return line. Clean fuel tank vent. Check fuel lines, fuel supply pump and injection pump. Replace fuel filter. Selective test nozzles and replace as necessary.

Problem

Noise rap from one or more cylinders.

Cause

Air in fuel system. Gasoline in fuel system. Air in high pressure line. Nozzle sticking open or with low opening pressure. Engine problems.

Solution

Check for cause and correct in fuel system. Replace fuel in fuel system. Bleed system in high pressure line. Replace defective nozzle.

Problem

Combustion noise with excessive black smoke.

Cause

Timing off. Injection pump trouble. Nozzle sticking open. Internal engine problems.

Solution

Rest idle timing. replace pump in injection pump. Clean or replace nozzle.

Ignition System Service

Checking and testing of the ignition coil primary winding and secondary winding resistance. By the use of multi tester, test the resistance between positive and negative terminal of ignition coil. The test must have 1.3 to 1.6 ohms resistance. Test secondary winding resistance between positive terminal and center tower terminal. It must have 10.7 to 14.5 kilo ohms.

Check power source line using the voltmeter, check voltage at the positive terminal. Turn the ignition switch to on position, connect the positive probe of voltmeter to the negative side of terminal to engine body or ground. Approximately 12 volts power supply.

Check primary circuit by checking lose connection in the primary circuit. Battery, ignition switch, ignition coil, condenser, contact point. Grounded circuit can lead to malfunctioning of ignition system and produce spark. Check the open wire.

Check the contact point for corrosion and burns produced by the electric arcing when contact point close.

Check the distributor cap from corrosion, breaks and oil. Carbon contact at the cap center tower breaks that it cannot contact with the rotor.

Check the high tension cable from cracks, scratches, burns and open insulation. This can cause spark when it touches engine body. Test the high tension cable resistance, It must less than 25 kilo ohms.

Check spark plug by conducting spark test. Inspect spark plug gap. The gap ranges from 0.8 mm to 1.1 mm. Clean the spark plug tip. Inspect porcelain insulation for cracks.

Inspect rotor and distributor assembly. Check rotor tip from corrosion or bend. Check also distributor shaft for play. Condenser wire and contact point wire must not be grounded at distributor body.

Engine Classification

Engine Classification according to Fuel Used

Gasoline Engine uses gasoline as fuel. This engine uses carburetor to mix fuel with air and form it into a vaporized form before it goes into the cylinder and ignited by spark plug.

Diesel Engine uses crude oil as fuel. Air is compressed to rise up temperature and fuel is injected into cylinder in atomized form. Hot compressed air ignites the fuel.

Engine Classification according to Method of Cooling

Indirect Cooling System usually called water engine. Water circulates inside the engine through water jackets and absorbs heat to maintain engine operating temperature. Hot water is being cooled to the radiator.

Direct Cooling System usually called air cooled engine. Air is blown by the blower to the engine body with air fins to absorb heat.

Engine Classification according to Cylinder Arrangement

Vertical or Inline Engine has cylinders have vertical center lines arrange one after the other.

Horizontal Engine has engine with horizontal center line of cylinders.

V Type Engine has engine block or cylinders resembles a letter V shape.

Radial Engine has cylinders arranged in radial manner.

Engine Classification according to Valve Arrangement

T Head Arrangement has valves arranged in both side of cylinder block. All intake valves in one side all exhaust on the other side.

L Head Engine has intake and exhaust valves arrange in one side of cylinder block.

F Head Engine have intake valves in the cylinder head and exhaust valves on one side of cylinder block.

I Head Engine has all intake and exhaust valves located in the cylinder head block.

Parts of Automobile

The major parts of automobile are as follows:

Engine is the main source of power. It is a self propelled device that can produce power by itself through conversion of chemical to heat to mechanical energy.

The power or drive train unit consist of parts that transmit the power from the engine until it finally reaches the wheels. The conventional type composed of clutch, transmission, universal joints, propeller shaft, differential and drive axle. 

The running gear system consist of accessory units that assist the engine and the power train unit in enabling smooth operation running and control of the automotive vehicle. Running gear includes steering system, brake system, front and rear suspension system, wheels and tires, shock absorbers, linkages, leaf and coil spring, torsion bars and other accessory units.

The body is the compartment where the operator or driver and passenger or car goers are housed. The body includes the dashboards and instrument panel, seats, seat belts, lights, mirrors, wipers, air condition and other paraphernalia needed to provide comfort and safety to both driver and passenger.

The frame is referred to as skeleton of the automobile where the engine, power train unit, running gear system and body are attached together unitized into a  complete automobile.

The chassis unit consist of all parts of the automobile like engine, power train unit, running gear system and frame minus automobile body.

Four Stroke Cycle

Four Stroke Cycle has the following parts air and fuel, intake valve, spark plug, exhaust valve, combustion chamber, piston and crankshaft.

Four Stroke Cycle has four stroke mainly intake stroke, compression stroke, power stroke and exhaust stroke.

Intake stroke is when piston move downward from top dead center to bottom dead center producing a suction force to draw air and fuel mixer to inter in cylinder from carburetor. The intake  valve is open allowing mixture of fuel get into cylinder. The exhaust valve is close to let only mixture get in.

Compression stroke is when the piston moves upward from bottom dead center to top dead center pushing the air and fuel mixture to get into a small space to prepare for combustion. The intake and exhaust valves are both close to ensure that no mixture of fuel escape from cylinder. At the end of this stroke, the spark plug delivers spark to ignite the fuel mixture until compression ends. In diesel engine, purely air is compressed to raise temperature and diesel fuel is injected at end of the stroke.

Power stroke is when the piston moves downward from top dead center to bottom dead center cause by the pressure produce by combustion or burning of fuel mixture. This is the source of power of an engine. The intake and exhaust valve are both close that no power can escape from the cylinder. Leakage of power during this stroke result to a low performance engine or lack of power.

Exhaust stroke when the piston moves upward from bottom dead center to top dead center pushing the burned gasses to get out of the cylinder. The intake valve is close and exhaust valve is open making a away for the exhaust gas to get out. At exactly end of this stroke, exhaust valve closes.

Engine Parts

Engine is a device that can convert chemical energy to mechanical energy. Since this device works mechanically, it composed of several parts that work together during the operation. Parts are either stationary or non stationary, meaning some parts are moving and some are not moving. There are also parts that are fixed to the body yet have the vital role for engine operation. Engine can be divided into three main parts, the cylinder head block, cylinder block and oil pan. This means  an engine can be disassembled into three divisions. Each main part have several parts are attached to form as an assembly.

Cylinder block is the foundation of the engine. It is mostly made of cast iron or iron mixed with other metals such as nickel and chromium. Cylinder block has large holes for the cylinder bores. Attached to the block is the crankshaft, connecting rod, piston with rings, oil pump, water pump, timing gears, flywheel, bearings, oil seals, piston liners, camshaft in some engine and drilled oil passages with oil filter.

Cylinder head block is made of cast from cast iron or aluminum alloy. Parts attached to cylinder head block are valves, valve spring, valve guide, valve seat, rocker arm assembly, intake manifold, exhaust manifold, overhead camshaft, spark plug, fixed machined or drilled parts like water jackets, oil galleries, intake and exhaust ports.

Oil pan is made of plastic or metal. Pan is shape to fit the bottom of the cylinder block. Oil strainer and oil drain plug are attached to this part.