I have a 2005 Mazda3 2.0L AT with 30,000 miles on it. I've had a bit of a problem with starting where it takes longer to start...usually around 3-4 cranks later from the usual 1 or 2. One day, it really had a heckuva time to start and I stopped after it was cranking it 6 times with no success. I then let the car sit a minute or two and it started with about 3 cranks.

Now, I am beginning to notice weak acceleration on hills. It's not struggling it just seems weak. I have now CEL at all.

The thing is I tend to fill up only when the low fuel light goes on. I hear mixed reports that that may be causing the fuel pump to go while others say it's not likely since even when engine light comes on, I have a couple of gallons of fuel in the tank.

I had the battery tested and it's fine.

I was wondering if the problem could be spark plug or PCV related? Or even clogged throttle body?? I believe I had the throttle body or intake cleaned a few years ago under warranty because it was gunked up...so the dealer told me. He also said it wasnt the worst clogging he has seen either.

Any ideas?

 

get the fuel trims checked , a bad #1 o2 sensor will cause all sorts of problems ...even without a code. short and long fuel trims ...no more than + or - 5% at idle .

 

a plugged fuel filter may contribute as well.
What's your MPG look like? if that's way off it would support the O2 sensor or maybe leaking injectors or something that would be flooding the engine.

and don't worry about running to the low fuel light - there is more fuel in the tank to keep the pump cool. I've gor 43K on my '07 and always wait for the low fuel light before filling - and no issues so far.