Need some diagnosis help
 

Hi and thank for taking the time to help me out. My 2006 mazda 3 with a manual trans. has been giving me an issue for the last couple weeks. When accelerating the car will start to jerk or shake back and forth. If I stop giving it gas it stops but it doesn't happen in 1st and 2nd gear (least I haven't noticed it) 3rd gear is when it starts to shake hard. Its definitely more pronounced when the car is cold and leaves after it warms up.

Now with winter coming around the drop is temperature seems to effect it more. Ah and also to note Ive been having bad starts with her too. It happens 50/50 that starting the car takes a long roll before it cranks up and "struggles" right before it does (little period of pause before it starts) To me seems like a fuel system problem but Im only a semi-novice when it comes to mechanics.

Any other questions please let me know

As far as the hard starts given you said it's worse when it's cold (and it's getting colder out). Do you still have your original battery? If so then it's probably ready for replacement given batteries are really only supposed to last about five years. If your cold cranking amps are low it could be affecting your morning start up.

It is the original battery, Ill bring it in to be looked at. Thought the 2 problems could've been related but not necessarily. Thanks for the pointer