Ask the mechanic : What causes a hard cold start?

One of the things you might have to replace to solve the hard cold start is the fuel filter if it is out of service. PHOTO BY RACHEL MABALA

Hi Paul I have a Land cruiser TZ Petrol 3490 cc 1997 model but it has a hard start every time it cools. I even tried to adjust the accelerator wire to a position 1 but it fluctuates back below. What should I do?
Hello, your Toyota Land Cruiser 3.5L petrol engine seems to have a hard cold start and low engine revolutions at idling.


I suggest your mechanic addresses the following:
1) Check/ clean intake air temperature sensor & mass air flow sensor to remove deposits.
2) Check coolant temperature sensor circuit or condition for corrosion damage. This sensor helps the engine computer to determine that the engine is cold and deliver more fuel for cold start enrichment.
3) Replace fuel filter if due for service.
4) Confirm condition of spark plugs and high tension leads for leak. Replace with genuine ones from Toyota.
5) Confirm condition of throttle body clean carbon deposits. A dirty throttle body will not allow the throttle valve to open or close freely. This makes the engine idle revs low.

Hi Paul,
I want to buy a Toyota Premio 2.0 but I am being discouraged that it’s consumption is more in relation to the the rest. Can you please give me what to consider before deciding on any of the above. Thanks in advance. Eric .M

Dear Eric, there are two generations of the Toyota Premios in the eleven generation Corona lineage. The pre 2001 Corona Premio is built with a 2.0 litre 3S-FE multi point via port fuel injection while the post 2001 Premio Allion comes with the 1AZ-FE 2.0 litre D4 (direct four) fuel injection with VVTi (Variable Valve Timing intelligent). My choice would be the better looking, more comfortable and more efficient post 2001 Toyota Premio with a 2.0 litre 1AZ-FE engine. The older 1998-2001 Corona Premio’s 3S-FE 2.0 litre engine delivers a power output of 126 HP (horse power) provides a fuel economy of approximately 16 km/ litre on the highway and 10 km/ litre in city traffic. On the other hand, the newer Premio Allion’s more powerful 145 horse power 1AZ-FE engine delivers a better fuel economy result of 17 km/ litre on the highway and 11km/ litre in city traffic. The Premio Allion’s better performance and efficiency is due to its direct four fuel injection and variable valve timing technology which reduces wastage by ensuring timely and appropriate delivery of fuel or air to the engine combustion process. Surprisingly the fuel economy of the pre 2001 Corona Premio’s smaller 1.8 litre 7A-FE petrol engine is the same as the bigger and more powerful 2.0 litre 1AZFE engine with D4. The above fuel economy statistics can be influenced by the engine service or tuning, kind of fuel and engine oil used as well as other factors such as condition of tyres and driving style (aggressive or relaxed). The Premio Allion’s D4 VVTi 1AZFE engine requires strict fuel and air cleaner maintenance with genuine parts.
D4 engines ought to use petrol fuel with detergent additives such as Shell Fuel Save or Shell V-Power to keep the intake valves free of deposits and prevent sludge and after burn deposit build up while protecting the delicate Variable Valve train system.


The VVTi system requires engine oil with detergent additives to prevent deposit buildup that is designed to keep in suspension during drain interval so as to promptly build oil pressure in the upper valve train area when you start the engine.

Hi Paul,
I am an elderly lady who has just leant how to drive recently and bought myself an old automatic Jalopy. It one time broke down when I was upcountry and it failed to go uphill. The car just rolled backwards and no matter how much I tried to steer it in the right direction, it could not go. I eventually took it to a mechanic, who cleaned the spark plugs and I drove home. I have several questions for you which I need answers to.
1. If the problem was to do with worn out spark plugs, why is it that I was able to drive the car all the way to the village and it only failed to go uphill when it had moved some distance halfway the hill.


2. How can I tell that the spark plugs need replacing? Maybe I had failed to notice anything.
3. Why wasn’t I able to steer it in the right direction when it was rolling downhill? I had already engaged the reverse gear. It had stalled after failing to go uphill. It could stop shortly after igniting.


4. How can I properly maintain it in a good condition since I rarely drive? At most I drive it twice a month. However, it was so old, everything breaking down and I had to install a used engine, a new drive shaft, CV joint, steering rack and pinion, brake calipers, pads, linings, brake pipe, oil filter, oil pipe, water pump, fan, ignition lock, timing belt, shock absorbers, wipers, reflector, dim lights, new battery and wheels. The expense has dug deep into my purse and am fed up. I almost want to stop driving. So please advise me on how best to maintain it and avoid expensive repairs.


5. What other repairs should I watch out for? It’s the transmission, fuel, steering pumps and exhaust system which haven’t yet gone down. The car was manufactured in 1993.
6. Is driving using the first gear D1 throughout ok?
7. I read somewhere about smart charger for a car battery. Is it available in Uganda and how can I obtain one?


Rita.

Hello Rita, I think the car you bought is a ‘money hole’ or ‘money drain’ of sorts. Considering the age and list of components you have had to replace so far I feel that you made a bad buy.
The failure to drive uphill is probably because it has a bad automatic transmission which cannot shift to the lower gears 2 and 1 for torque.


This is suggested by the fact that the car was able to drive up the gentle slope but could not continue further uphill. This conclusion is supported by the fact that you probably have to drive with gear D1 to be able to take off. By the way selecting gear D1 allows you to move your vehicle using only one gear number 1 in case you are stuck in the rut or are towing. However this gear does not shift, you need to revert to D to experience automatic gear shifts up and down.


The list of parts you have already replaced indicate that this vehicle is aged, probably has a poor maintenance record and will continue draining your pocket. Cut your losses by selling this car and moving on to a vehicle with a better maintenance history. Next time take a trusted technical person to help you pick the car you fancy.

Ask the mechanic
By Paul Kaganzi
0772316145
send sms: mycar (space) your comments and questions to 6933, or email them to [email protected]