Im new to this forum, and a new owner of a 1990 white Camry V6 2.5L GX-i (MT). I have to say, this forum is simply great! Ive learned a lot about my Camry and cars in general thanks to it. Im very new to cars and how they work, but ive started reading a lot and wish to fix as many issues as i can by myself.
Anyway my car has got some issues seemingly very related to this thread so i post it here instead of creating a similar one.
When started cold, its no problem. But when the engine starts to warm up and the car is in motion, it starts to hesitate and or knock at low RPM such as <2500-3000, especially at gear 1-3. Other times, this doesnt happen at all. And usually, after the engine and car in general is thoroughly warm, the knock only starts at very low RPM such as <1300. It idles pretty rough as well, and the rough idle happens at the same times as i told about the car while it is in motion. When the car doesnt knock or hesitate in motion, it also performs perfect idling. At worst tho, it might stall, but that has only happened couple of times.
When i drove the car the first time, and the first week after i bought it, it had much less trouble with this "knocking/hesitating". It started to get noticable after i drove the car almost out of gas one time and when i drove to the gas-station it really knock'ed a lot. After filling up some 10-15L tho, it still continued with the knocking as i told earlier.
After talking to friends and colleagues about this, i got hints that the issue might primarely be that the gas tank might contain some moist that gets to the fuel injector and is causing it to mix wrongly air and gas, or something like that. After hearing this i bought a small bottle of anti-icer for aprox. right gas tank and filled it up and also filled the gas up full correctly according to the instruction of the de-icer. Not at first, but slowly and firmly the knocking, and hesitation in the throttle has started to fade away almost back as it were before it first started to elevate to the really annoying level. But i feel there is something more wrong, the engine still knocks way more than im used to normally, and it is still more of an rough ride than i wish of this or any car. Also, the gas mileage seams to be poorer than usual cars with similar specs, but im not so sure since i havent really checked it thoroughly enough. But its something to have in mind as well. Also, seems like the weather effects all this as well, air humidity etc. But i cant be sure, the issue seems random at times.
Are there parts that i especially should look further into for tuning the engine to run smoother? Help is heartly appreciated