S14 Spitting Black Smoke
 

Hey guys so I have an S14 Zenki with the SR20DET Black top Engine, I just changed my differential with a R200V Diff but used my old Welded Flanges on it because I had no other ones. So I was driving out of a Safeway parking lot and while in gear like 1st when I started releasing gas so it was rolling in 1st gear it started jerking back and forth, so I put it quickly into neutral nothing happened. Then driving out I put into 1st accelerate then 2nd gear, and it did that once again jerking the car back and forth while Black smoke was coming out of the back. So I parked my car , went to a friends house came back , started my car. At that point it seemed to run fine just standing there, so I decided to try and drive it home, because I don't wanna leave it in a abandoned parking lot overnight, and surprisingly I drove home totally fine, my car wasn't jerking or spitting out black smoke. Can anyone help me out with what this problem was. I havent drove my car ever since , like 2 weeks. I thought it was maybe the new diff but I dont know for sure, can someone give me some advice on what this might be thanks.

diff issues wont cause your engine to spit out black smoke, and since it was fine after letting it sit for a while im leaning towards a sensor issue check out the MAF it could be on its way out

^^ yuuupp!
And always check your grounds and look for shorts in your wiring , and no! not the ones u wer but the ones that cuase nightmares!

alright thanks it has a z32 maf installed on it right now .