Ant28

Hi, I too own a Lancer ck1 1999 carb model which came brand new to Sri Lanka. Reference to your description it could be couple of things which leads to this issue in this model. If you consider the carb, it purely works with vacuum pressure generated due to piston movement. Since you mentioned that it was diagnosed as petrol metering piston bent and it is something which should be physically checked with necessary tools. To bent or warp this piston is a rare situation unless the system is exposed to extreme heat condition. Probably the metering needle connected to the piston could be bent or the special coating in the piston could be damaged which leaks vacuum pressure and increase the friction. Please check these components thoroughly. Run the engine and once it gets warmed up to the operating temperature slowly open the throttle plate and see the movement in the piston. check the opening at the idle position and check the movement when you open throttle. It should move freely without getting stuck at any point. There are vacuum pathways inside the piston holder and most of the time they get plugged up with carbon or dust. If the piston movement is not consistent. Remove the piston holder cover. once it is removed check the sliding movement of the piston inside the ball baring track in the piston holder. if it is smooth then ok. Otherwise clean it with carb cleaner or petrol and lube it slightly to get a better and smooth motion. Check for any scratches or damage inside the holder. If above is ok, since you mentioned that car runs bit ok when warms up, I feel that you should check the auto choke system. There is a Vax choke system which works using the heat of the engine coolant which comes in to your carb. When it is disassembled you can see that there are few vacuum controlled gates or switches in it. You have to check whether they are working and if not clean them with carb cleaner or petrol and must change the gasket. Blow some low pressure air in to these path ways and see whether the gates open. If it is ok check the base gaskets and the "ebonite" spacer in between for vacuum leaks. If they are bad change with new gaskets. If every thing checks out then there are O rings in the main jet mechanism. There are 2 O Rings in the main jet and a another inside the jet adjustment screw which needs to be changed frequently since they go bad very often. There are another O ring inside the pilot air screw which is very essential to adjust the A/F mixture and another in the anti dieseling valve. These are the main O Rings which affects and controls the vacuum path ways inside the carb. Try replacing these. Then there is a accelerator pump mechanism which provides additional fuel shot every time you depress the gas pedal. Clean this path way and check the membrane of the pump for any faulty. If every thing checks out finally I can say that there is no major issue in your carb. If above doesn't fix your car try checking your ignition current distributor and spark plug wires. Distributor consist of inbuilt ignition coil, mechanical advance unit, vacuum advance unit pulse generator coil, igniter mechanism, rotor mechanism, Rotor cap and finally spark plug wires. Check any of these components are faulty which could lead to miss firing or bad ignition spark. There is a guy called Sarawana (0755120017) at walipara (panchikawatta), who do distributor work. I hope that I gave you some idea how to fix your problem or some guidance where to look for. cheers!!!!!