My girlfriend is having issues starting her 2005 Mazda 3. It sometimes will take 15+ cranks until it starts, with no relation to the cold or any other variables I can think of. Also, right after start it will have a slightly rough idle.

My guess is a bad fuel filter, but I need some other opinions.

Car has approx 51,000 miles on it, and the manual states spark plugs and filter replacement at 75,000.

We have tried fuel injector cleaners and whatnot, but no luck. I was thinking of maybe trying a can of seafoam in the gas tank but wanted some other opinions as well.

Thanks!

 

Leaking fuel pump? Bad crank or cam sensors?

 

No visible leaks or smells coming from car.

Happens about 50% of the time (stuggle to start).

 

^^^There is a check valve that's inside of the pump that is supposed to hold pressure. When this valve starts to go bad, it won't hold gas (leaks down) and then it takes a while for the pump to build up enough pressure to start the car. You'll need a fuel pressure gauge to rule out the pump though!

 

She has no knocking or shaking of the car so I doubt it is anything really mechanical with the engine.

Fuel pump possibly. How about the air filter? Could that cause it or would it be consistently struggling? Seems like it would be more "linear" with an air filter.

We have tried fuel injector cleaners and all that and our next step was seaform and replacement of air filter. If still no luck, im guessing it is the fuel filter or pump.

 

how many miles on in? i would swap the air filter and fuel filter next