Im trying to piece this together in my head so bear with me…ive been chasing this little weird idle / startup / bogging thing which comes and goes from time to time and is never quite the same
the results from pulling the ecu to check codes are inconclusive.
Lately what im noticing is that from time to time, especially when its warmer outside, if i give the car full throttle, it hesitates and bogs, anywhere over about 3500 rpm. Its somewhat inconsistent. It actually seems quicker if I dont floor it but almost floor it. In fact the odd time if you go from say 85% throttle to 100% throttle too quickly (ie all at once) the car will pause for a sec then accelerate no faster than before.
It seems to be sensative to the outside temperature. It rarely reacts this way if its cooler outside ie nighttime but a few weeks ago i was driving at about 130 kms for a few hours straight, and it was warm out, the engine bay was hot, and i downshifted to pass someone, floor it, and it bogged rather badly. I use regular fuel, but i know the car does this on super too.
but
when you open the throttle fully , the computer ignores the sensors right…meaning I think, that this hesitation is not caused by a sensor sicne it tends to only happen at full throttle, lately. The fuel filter, plugs, air filter and all that stuff are new too.
Its getting to be that my engine has two distinct personalities. Some days it idles smoothly, the idle is steady, plenty of power and pep, no bogging, etc, and other days it is the total opposite, with idle dropping under 500 rpm briefly when coming to a stop, sputtering during moderate acceleration, bogging when you floor it, and even sounds rough exhaust wise.
Other Symptoms:
-Sometimes i smell a whiff of fresh gas outside the car, though there is no visible leak
-My dad was going for a bike ride and saw me downshift and punch it to avoid a yellow light, and he said there was a fair amount of black smoke coming out the exhaust (running rich?)
-I installed a used MAF that was “tested and working” once to see if that worked, back when i thought it was a sensor. The car wouldnt even start with that new maf.
-A friend of mine thinks it could be timing related but i thought if that were the case it would act the same all the time.
Engine is a ka from a 1993 with 250 kms, intake and exhaust with header, and it has a cat
any ideas?
