Hey Scotty! I’ve been blessed with a beautiful 1999 Corolla (automatic transmission) for my first car. Unfortunately I Left the house this morning with it sputtering out of nowhere. It’s pretty tamed and didn’t give me any big problems on my way to and from school. When I accelerate (say 0 - 10 or 15) it sputters before smoothing out into the desired speed. It also sputters slightly more in idle when the AC is on full blast. I’ve looked up on forums everywhere with no solid result. I believe it may be a bad spark plug(s) but the web says it may be otherwise. Got any idea what it could be?
How old is the fuel filter?
Not sure but the car has more than 200,000 miles on it so I’d assume it’s the pretty old. There’s a brand new cold air intake I installed in it. I’ll give it another look with my father.
The cold air intake (new) is probably messing up your engine. They look nice when you open the hood but do not work well with computer controlled, sophisticated engines, even one as old as yours.
Found a slight heed of issues
Extremely low oil
Dirty throttle body
And lastly (and quite frankly dumb on my part) last week I poured some fuel that had been sitting in a gallon for a couple weeks from when I had cut the lawn. I’m not mechanically inclined but I’m pretty sure old fuel doesn’t burn well. We filled her up with some more oil and cleaned the throttle and when we took it for a spin the sputter wasn’t as bad. I think I’ll drive it for the rest of the week and burn the rest of the fuel. If nothing changes when I refill her and she continues to sputter I’ll look into changing the air intake. Thank so much for the help doc!
Many possible causes; air filter, fuel filter, fuel pump, spark plugs, coils, dirty MAF sensor and/or throttle body, vacuum leaks, and more. Start by scanning it for codes and live data.
