hello, i just bought this used rx7 and i driven a couple of times but the times i started it i always had to jumpstart or roll start it. one day i tried roll starting it with my friend but we couldn't get enough speed so we pulled it over and tried jumping it. my friend switched the positive and negative wires by accident and i started smoking a little and thats when my car completely died. none of the inside appliances work and the even the dashboard wouldn't light up. i thought it mightve been the batteries so i switched it and the same problem is happening.

 

You've probably blown fuse(s). I'd start with the main 120 fuse next to the postive terminal. But check them all....EGI relay too.

Hard starting could be alot of things. Start with changing plugs and making sure your battery isn't going south and grounds are good. There's one from the engine to the chassis near the plugs, another from the rear engine hook to the firewall and another from the aft cat flange to the chassis. The latter is needed for the O2 sensor and tends to break or get fouled over time. Some quality fuel system/injector cleaner couldn't hurt. I like BG44k or Chevron Techron if your on a budget.

 

Once you check all of your fuses...reversing polarity on a battery is no joke...that can kill a car my guess is you are either looking at...

Worst Case Scenario: Engine that has low compression
Best Case Scenario: Need to jumper your clutch interlock switch.

 

how do i check/fix them? can it be done at home?