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we have a Daihatsu materia 2005 , we replaced the plugs,cam sensor , petrol pump, body sensor, air intake temp and catelis converter. The car drive fine when cold, but after a few kilometres it doesn’t accelerate when pushing the petrol pedal and sounds like it’s smothering.
Changed coil 1 and 4 , still the same. What else can be wrong?
Diagnostics say misfiring on all 4 cylinders.
Car only got 64000 km’s on. Fuel pressure 3.5
Have you replaced the air filter? How about the mass air flow (MAF) sensor? Replace the PCV valve. Check for disconnected or broken vacuum hoses. You may have a bad tank of gas. Check the operation of the EGR valve (verify that it is not stuck in the open position). Does the fuel pressure remain good during acceleration? I don't understand what you mean by "body sensor" -- perhaps throttle body/throttle position sensor?
That seems like very low km's for such an old car. Was this car driven very slowly for more than a few months, for short trips under 15 minutes, without ever driving on the highway for more than 20 minutes? If so, there may be excessive carbon buildup on intake valves and combustion chambers, especially if driven in cold weather. If the old spark plugs were heavily blackened, there is excessive carbon buildup for sure. If the car was sitting unused for a long period, or the crankcase oil was not changed periodically, or the gas was contaminated, the valves may be sticking. I have personally experienced these situations with cars used by the elderly, reducing acceleration to practically nothing.
