After an engine overhaul, my car does not start

Thursday July 23 2020

 

By Paul Kaganzi

Hello Paul, I have a Toyota Windom 1997 model with a V.6.engine 2500Cc. I have replaced all engine parts from valves, rings and gaskets but the engine has failed to start. What do you think is the problem? Bitature

Hello Bitature, there are a couple of reasons the 2MZFE V6 engine in your Toyota Windom may have failed to start after the engine overhaul.

Ordinarily, the engine starter turns the flywheel and subsequently the crankshaft ignites the fuel air mixture to start and keep your engine running. Ensure that that the electrical system provides sufficient power to turn the starter motor.

For an engine to start and keep running, it needs sufficient fuel pressure; a properly and accurately timed ignition system or spark and normal compression. Short of the above conditions, you will have a crank but no start condition even after engine overhaul.

Get a qualified mechanic to safely confirm that there is sufficient fuel pressure using a fuel pressure test kit. If the fuel pressure does not meet the recommended values, confirm the working condition of the fuel pump and rule out a clogged fuel filter or dirty faulty fuel injectors.

Review the ignition system by checking the ignition module, crank shaft position sensor, ignition circuit high tension leads or coils and spark plugs in case they are bad. Your mechanic should carry out a compression test using a compression test kit.

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All engine cylinders need sufficient compression. Compression is the confinement of an appropriate mixture of air and fuel into a small volume within the area of each cylinder for ignition to produce engine power.

To achieve sufficient engine power, the air fuel ratio during compression must not be too high or too small. Low compression can be caused by the fuel air mixture from combustion leaking past damaged or improperly fitted piston rings and worn out engine cylinder walls.

Compression problems can be caused by a damaged timing belt or wrong ignition timing during engine rebuild. Ask your mechanic to try using a compression test gauge or refer to a timing reference guide for the 2MZFE engine in your Windom. Refer back in case you still meet challenges.

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