Toyota Corona Problems

CHECK the engine is a Toyota engine because Toyota was fitting the Holden 1.9-litre overhead-valve four-cylinder engine to the Corona at that time. The capacity you quote suggests yours has the ``misfire'' four in it. If it's a Holden engine the compression ratio was 8.7:1, but it's likely to be less than that now. If it runs well I'd continue to use unleaded with an additive.

ACCORDING to the government guide, your car cannot run on unleaded petrol without an additive, so the best advice is to run it on regular, or premium unleaded if you can afford it, and add a commercial lead replacement additive available from your servo.

YOU can cause a problem putting too much oil in the sump. The crankshaft hits the oil as it rotates, which can put extra load on the engine, reduce performance and increase fuel consumption. It can also cause the oil to froth and cause problems in the lubrication system. However, adding an extra 200ml probably won't have too much effect.

I haven't heard of any problem in getting LRP in your area, but I will check with the fuel companies. The engine in your Toyota should have valve seat inserts which means you could simply switch to ULP without the need to use an additive. PULP would be a waste of money in your car when it will run happily on regular unleaded.

There were reports from Western Australia of a build-up of deposits on the spark plugs of engines running on LRP and which were driven only short distances. The deposit was blamed for poor starting and running, so it's worth checking your plugs for abnormal build-up of deposits. Clean the plugs before reinstalling them in the engine. If there is an unusual build-up that could be causing the problem, consider changing to a higher heat range spark plug that would help burn off the deposits. While there is a chance the problem is caused by the LRP you use, it's more likely to be a problem with the engine itself, so check the carburettor to ensure the automatic choke is operating correctly, and check the ignition timing, points and set them to specification. Also check for signs of intake manifold leakage.