I have a 2011 Mazda 3. About a month ago I was having a problem where when I'd try to start the car, it wouldn't turn on and the gas cap light came on. I could get it to turn over by revving the engine a couple times, but it struggled to get there. Took it to a shop, they replaced the gas cap and it was fine.

Fast forward to now, car is doing the same thing. I can turn the car on, the lights come on, everything, but the engine won't turn over unless I rev the engine a couple times. Once the car is on, it stays on and runs fine. I took it back to the same shop, they said the throttle body is dirty (109k miles) and that was probably the issue.

So they removed the throttle body, cleaned it and when I picked up the car, it started up fine. Next morning, same issue happens again. Everything I read online says maybe the fuel pump (which the mechanic did say today when I called him again) or a relay switch (?). If anyone has any ideas or has had this problem, I'd appreciate some input before I let someone experiment on my car for a few days :/

ETA: battery is only 4-5 months old so that's not an issue...

 

Did you ever grt this fixed?

 

Based on previous experience, my guess would be the pressure regulator inside the fuel pump assembly leaking off fuel pressure.

 

I did actually. I had one of those little trackers plugged into my car for my insurance company, that monitors your driving for discounts. It apparently was faulty and was completely screwing up the cars computer system and causing all the issues. I had to take it to the dealership before anyone could figure it out, they unplugged it, ran some tests and figured out that was the issue. I'm actually involved in a class action against my insurance company now because apparently this is a pretty common issue and some people have had way worse happen to their cars.

 

I thought mine was the pcm, replaced and still no start unless i pound the gas. I was looking in to the fuel pressure regulator as a issue but could not find it. So in the tank attached to the fuel pump Assembly? Doesnt matter to much ill habe to replace the whole unit.