I have a 2004 Daihatsu Sirion (+ 200,000 km) which has inexplicably started losing power at medium to higher revs.It has also generated a lot of heat. First diagnosis was a problem with the catlalytic converter, but this was gutted and made no difference (the core was cooked though). No further mechanical problems have been found. Diagnostics indicated possible problems with the mapping and crank sensors, but these were tested and found to be OK - ditto the "mother board?" The petrol pump has also been removed and checked without resolution. Any other possible solutions would be greatly appreciated.RegardsGary
Hello and Welcome to justanswer..You will get readings saying such sensors are playing up when you get such problems as this even if they aren't sometimes - this is because the situation you have , the cause of the problem, is having a knock on effect , so you cant always rely on that / readings.. other / fuller tests have to be done first .. When the problem is sorted, the other "faults" will clear.For the engine to be losing power - or suffering power loss, coupled with excessive heat build up, if its not a restriction in the exhaust, then its generally a valve / ign ( engine ) timing problem.. So this is what needs to be carefully checked now. The timing has to be spot on - it sounds like for some reason its become retarded - that will give you the exact symptoms you have - again.. loss of power and excess heat build up.IF its found not to be a valve timing issue / timing out for whatever reason to be found, and its proven to be an ign timing fault, the timing (ign ) is computer controlled and cannot be adjusted - in which case, the fault would be the main ecu itself ( which you referred to as motherboard I imagine ).. That would have to be sent off to a suitable competent test / repair centre to be cured. Such problems with the engine timing / ecu faults or misfires for reasons such as ecu or ign coil faults, will account for a "cooked cat" too....Just one one other thing though - to check just in case - I note you have removed the cats innards - but you can also get a clogged silencer box...so you must check that too - in case thats all it is.Assuming all else / other tests / checks have been carried out,then it leads to the above - so thats what you need to concentrate on now to get this fixed.Im very pleased to have helped you - Please click the Accept button for me now - Thank You ...and if you do need / wish to get back to me after - you can do so just by coming back to this post and use the Reply button - your reply will then come straight back to me .. and Im always happy to help further.... .Kind Rgds to you - MIKE.