rjkboyle

Hey guys, bought a M3 a couple months ago and have been lurking this forum for a while. Having some strange issues and hoping maybe you guys can give me ideas. I haven't been able to find anything completely similar online.

2007 Mazda 3
GT Sport Sedan
178,000 KM
5 speed

I will go out in the morning it will fire up right away no issues, run like a champ all the way to the train station.
I will get off the train coming home 8 hours later, fires up within a second again and runs great all the way home.
Get home change out of dress clothes, and with in maybe 15 minutes hop back in the car to head to the girlfriends house. The car takes >4 seconds to start and runs rough for a couple seconds, but then idles fine. I back out of the driveway and go to start driving up the road and all of a sudden its like I cant drive stick anymore. Its like im not giving it enough gas when pulling the clutch out, if i put the clutch in a little more and give it some more gas then let out its like the car is bogging out and either barely gets going up the hill, or all of a sudden launches up the hill like im dumping the clutch with RPM's at 4500k. This only happens when the car is warm, after running shortly before.

I have suspected maybe a fuel pump or something, and tried turning the key on for 2 seconds, off, then back on for another 2 seconds before cranking, and it seems to have helped a little but it definitely still happens.



Cliffs TL/DL
- When car is warm it cranks over for 3/4 seconds before starting. But then runs fine.
- Bogs out when starting in 1st gear and need to give it more gas and either continues to bog until moving or launches.
- When car is started cold, drives fine, and no bogging when starting in 1st (so i know its not because im bad at driving stick)


Anyone experienced this before?

djs2571

I'd guess that there's a temp sensor that's going bad. There's an engine temp, and an air intake temp (which is different from outside air temp that may show up on your dash if you enable the trip computer). If you get a scan tool you can look at the intake air & see if it looks ok.
Hard starting could be leaking fuel injectors, and that's close to the mileage they may start having issues. You can look at the exhaust when someone else starts the car to see if there's black (extra fuel) or tell tale smells of fuel when it's started warm vs in the morning / evening.

BTW, I know on mine (07 GT) when the engine temp gauge is about 1/4 the way up I feel the fuel mapping change. Similar to your comment about feeling like dumping the clutch - not that dramatic, but a definite shift in power without having my foot move. So you may want to check the VIN & see if there are any ECU reflashes that may not have been performed.
If that doesn't do it, clean the throttle body and see if it was something sticking there. Otherwise i'd guess some solenoid is sticking, though I don't know where to start figuring out which one since I haven't looked into what controls are on the engine.

rjkboyle

Alright guys so bit of an update here.

Got a CEL yesterday when driving home from work P0126, everything I find online suggests a thermostat problem. But all these cars that show this issue are on 04-06's with the older style thermostat. Not sure if I should just bite the bullet and replace it anyways? Maybe do the temperature sensor while I am at it.

But now to try and tie this into this thread, is there anyway this could be related? From what I can tell not, but this is definitely an additional problem if nothing else.