COMMON ENGINE PROBLEM
Possible Fuel Problems.
Although obvious this is the most common cause for an engine failing to start. Your fuel gauge may show there is fuel present however the mechanical measuring devises can be flimsy and prone to wear or clogging from any contaminated fuel giving an inaccurate reading.
How to check For Fuel.
Locate the in line fuel filter and have someone turn over the engine and see if you can see fuel passing through the filter or fuel line or,
Take off the fuel cap and place your ear close to the opening and rock the car gentle from side to side and listen for the fuel sloshing around or,
A fool proof method, get a can of fuel and put it in the fuel tank!
Note: If there is fuel present but its low and your vehicle has been stood on an incline this can cause fuel starvation. If you have a primer pump in the engine compartment squeeze it three or four times until it stiffens up and try to start the vehicle again.
If your car has a fuel primer pump it will look something like this. They come in a verity of colours often quite bright if they have been replaced.
If it starts it may stop again when what was primed has run out so get a can and fill her up.
Fuel present but wont Start
Petrol cars:
Depending on the age and type of car you may have a carburettor or a fuel injection system. Either could be faulty or have blockages which is unlikely but never the less possible this being the case professionals will need to take a look as taking a carburettor apart to clean requires considerable knowledge and electronic fuel management systems can be tested quickly and easily with specialist electronic equipment.
Diesel Cars:
Diesel cars require heater plugs to warm the fuel to a temperature at which it can combust. Each cylinder has a heater plug and they are consumable items which perish with use. They can be checked by removing them individually and examining them visually. If they are disfigured or black with soot the chances are they need replacing.
This shows the difference between a worn glow plug and a new one, the latter being on the bottom. Click on the image to view a larger picture.
Any main dealer or auto parts retailer will stock them and they vary in price depending on manufacturer. It it's always recommended to buy genuine plugs for the make of your car as they last longer but expect to pay more.
Possible electrical problemsModern cars have become more dependent on electronic management systems and as a result have become very complex. There is an upside to this however as computer diagnostic equipment can be plugged in to your car and for a cost of around £50 you can get an analysis which could in the past have taken hours and come with a hefty bill.
Electrical problems are more likely in a petrol engine as in order to run you need fuel, ignition and compression and a diesel needs only fuel and compression but does need electrics to initially fire.
Petrol cars:
If there is no spark there is no fire. Remove the spark plugs and check they are in good condition. They should be a light brown in colour, dry and undamaged. If they are white, oily or wet with fuel you could have fuel/air mixture problems and/or worn cylinders or piston rings and possibly leaking valve seals. This being the case a mechanic is a good idea as cleaning the plugs will only be a very short term fix.
Check for a spark
Obtain a spare spark plug you know is working and one by one so you don't mix up the plug leads disconnect a lead from a plug and insert the spare. Place the spark plug metal to metal somewhere on the engine to earth it and get a friend to turn over the engine. You should see a bright spark between the terminals at the end of the plug.
If all work then remove each spark plug one by one from the engine replacing the removed plug with the spare so you don't have an open cylinder and repeat the exercise.
No spark from a working spark plugThis could be the plug lead or the distributor/distributor arm. Remove the distributor cap and look to see if the the rotating arm contact point and contact terminals are worn this will be quite apparent if they are. They may also be corroded with a green oxide layer which can be cleaned with sand paper for a temporary fix. If the terminals and arm are worn then they may be no contact so replace them. Same goes for the plug leads, check for corrosion on the connections and if you have a circuit tester make sure current can pass along the lead.
Wrong compressionIts best to leave compression testing to the professionals as you will need specialist equipment. And if there is a compression problem it may be a major fix such as replacing piston rings or a head gasket.
Diesel Cars:
If you have already examined the heater plugs as described above and found them to be in good shape you can test them by removing the plug. Making sure the plug is still attached to the connection wire place the thread used to screw in to the cylinder head on a metal part of the engine. Keeping the element clear of anything in the surrounding area (including your hands they get hot! Use pliers or vice grips) have a friend turn the ignition to the on position but not all the way. You don't want the engine turning over with an open cylinder. If the plug is working properly it will glow beginning at the tip and moving upwards. Switch off the ignition and repeat the exercise with the remaining plugs.
Heater plugs working but not glowingThis could be a result of poor connections or a faulty heater plug timer relay which controls how long the plugs receive current. Remove the inline connecting wire and clean the connection points and when replacing ensure the connection nuts are secure. Using a circuit tester on the wire will fitted will help trace the problem back to the timer relay.
Remove the timer relay from its connection point and check the terminals are clean. Use sand paper if they are corroded or replace it with a new one.
In the case of both diesel and petrol cars check the fuel filter and air filters are clear and free from build up. If they are dirty or contaminated replace them. An engine starved or air will run rich and be inefficient both in performance and economy.
Incorrect timing
All internal combustion engines require a host of events happening in the correct sequence at the right time controlled by a timing belt or chain. If a timing belt or chain becomes loose or worn it can slip or jump if this happens the sequence of events required for an engine to run correctly will will be out of step. The same result will obviously occur if a belt or chain is fitted incorrectly. Setting the timing will require a manual to find the settings and is best left to a qualified mechanic as if it is set out of time too far you can cause engine damage such as bent valves which can become expensive.
THIS IS BROUGHT TO YOU BY
PROSPER COMPANY LTD.,
KEI OOMORI
kei@mercy.co.jp / +81-50-5539-9816
