A Lamborghini in Ug! Is it a joke?

Qn.I own a 1994 Mercedes Benz E 280. Looks like the fuel or fire is not working. Could the immobiliser be the reason for the car not starting if the engine is turning? Engine turns but does not start. Haruna Sekiziyivu

Ans.Your Mercedes fuel and spark delivery are authorised and regulated by the engine control unit. Assuming that your spark plugs, fuel injectors and throttle potentiometer are all fine, there several intermediary factors that could cause a breakdown in the system and prevent your car from starting.
Without the benefit of checking your car I can only give you the possibilities. The immobilizer locking you out is one possibility in case there is an electrical circuit break down or a damage of the transponder system in the key, hence breakdown of communication with the key reading system.
However, there are other issues that restrict fuel supply such as the fuel pump failure or the crank angle sensor. A computer diagnosis will cut the long story short by pointing you in the right direction.

Qn.I drive a Subaru Forester. It drives well on low speeds, however when I accelerate to 160kph, the check engine light displays on the dashboard. What could be the cause?
David

Ans. The check engine light comes on when the Engine Control Module (ECM) recognises a malfunction with an emissions control device monitoring system or if a specific condition is not being met. In your case, you need to make sure that the following factors which affect emission are in order: spark plugs, air filter, no leaking vacuum hoses leading to and from the throttle unit as well as the fuel filter. It is also essential to check that your car exhaust catalytic converter is not damaged. Should these serviceable items be okay, carry out a computerdiagnosis to ensure that engine sensors are okay.

Qn.I drive a Toyota Mark II Grande Regalia GX 110 and have lately been experiencing signs of loss of power whenever I step the gas pedal in the mornings (that is before the car is driven at all. The symptoms manifest as if the car is losing power and is about to turn off. It happens when I step on the gas pedal when the car is still in the parking gear, then repeats it in the reverse and drive gears. The problem seems to disappear after the car is running. Initially I was using the single filament spark plugs but two months ago, I replaced them with the Denso double platinum spark plugs similar to those in the Toyota Harrier. Secondly, the vehicle has been producing whitish smoke and burning oil and requires replacement of half a litre after a journey of 150 kms or thereabouts. What could be this car’s problem? Jeffrey

Ans.Your Toyota Mark II needs to be inspected in order to confirm the extent of engine damage. Loss of half a litre of oil every 5,000 kms can be explained, but half a litre after 150 kms is serious. Assuming there is no oil leakage around your engine, oil loss can only be explained by damaged engine valve seals, valve guides or piston rings.
The oil that leaks past these damaged parts infiltrates the combustion chamber. When your
spark plugs ignite the fuel-air (and oil) mixture you get an inefficient combustion cycle. This results in loss of power upon starting and the unusual exhaust smoke.
As you drive there is a pattern of intermittent loss of power as the spark plugs burn the oil and it re-infiltrates the combustion chamber.
The colour of exhaust smoke you describe as “whitish” is a contradiction as white smoke is often a result of engine coolant leaking into the engine combustion system due to a damaged cylinder head gasket. Confirm that the smoke you see at engine start up is actually not blue-gray, which would confirm oil leakage to the pistons. You have not been maintaining your car well. Unfortunately, there is no shortcut or quick fix for this one. You need to open up your engine to confirm extent of damage to your pocket or else your car will become a mobile grandmother’s kitchen chimney.

Qn. I enjoyed reading your magazine last week, especially the article about the dangers of winter tyres. I am trying to buy new tyres for my Toyota Fortuner. I wonder which tyre dealer in Kampala has genuine good tyres? What is the best tread pattern and can I upgrade my tyre size from the Toyota recommended width size 265 to 275/. Roland.

Ans. There are several new tyre dealers in town who stock reputable brands that are manufactured to meet the highest standards of road safety and performance.
The choice of tyres you buy will depend on the purpose, operational terrain, availability and budget, of course. If you are a city commuter who goes up country once in a while, you need to buy all terrain tyres.
These tyres have stiffer sidewalls for greater resistance against puncture when travelling off-road, the tread pattern offers wider spacing to remove mud from the tread. Many tyres in the all-terrain category are designed primarily for on-road and occasional off road use.
When upgrading your car tyre size, you should be guided by the tyre size and pressure manual on your door pillar.
If the upper limit of the tyre width is 265, upgrading to 275 causes a risk of the front tyre touching the inner wheel well or shock absorber whenever you turn. Besides the car manufacturer has calibrated the suspension matrix to work best on the 265 tyre width.

Qn. I am based in Kibale. I enjoy reading this magazine. I have been saving money to buy my first car and I now have a budget for a small car. I am looking at buying either a Premio or an Ipsum. I do not have any idea about how to buy a car, Can you advise me what to do. Arinaitwe.

Ans. Arinaitwe, buying your first car is not as simple as buying a bicycle. You need to use your wits and a lot of common sense. Having decided what type or size of a car suits you i.e. Toyota Premio or Ipsum the task ahead is to find a good car.
The factors you need to consider before buying a car are: technical condition of the car; legitimate registration and ownership of the car; absence of dues, parking fees or outstanding loans attached to the car. Today, there are rampant car thefts, falsification of registration and title of ownership as well as defaulting debtors who have used cars as security. Uganda Revenue Authority can help verify the registration and ownership of the car. The local authority parking contractors can confirm that this car does not have any dues. A good mechanic can help you vet the technical condition of the car before you part with your hard earned money. It is important to sign an agreement, in the presence of a lawyer or local council authority, with the confirmed registered owner of the car before you pay.

Qn.My 2.5L diesel 1992 Toyota Hilux Surf engine spills oil through the dipstick tube especially on acceleration to attain high speed. What could be the problem? Nick.

Ans.You need to check the Toyota positive crank case ventilation (PCV) valve which helps to release accumulated vacuum build up from the engine combustion process.
Sometimes, this vacuum system is blocked by sludge or carbons build up. The vacuum building up in the engine will find an alternative release point through the dipstick chamber forcing some oil out of the engine in the process. A similar issue is common with a blocked Electronic gas recirculation system (EGR).

Qn.My 1994 Isuzu Trooper auto V6 DOHC is hard to start when the engine is cold and after it starts the idle is sporadic and will die when it is put in gear, it will also die if you tap the accelerator when it is in park or neutral. Any advice? James Okello

Ans. Cold start problems can be caused by several issues. A faulty coolant temperature sensor will prevent the cold start enrichment function.
Worn out spark plugs, a dirty air filter or fuel filter can cause the problem you are describing. A dirty air filter will allow soot through and this will affect the throttle potentiometer. A computer diagnosis may check and confirm if the idle air control valve is faulty.