Car is Misfiring

[OldmanPurdy]

Hi guys Im having a real problem with my 91 240sx (ka24de). The car is misfiring BAD, I barely got it home today had to restart it like 4 times. This problem started small about 5 months ago, it would miss here and ther but it would keep on going, Then slowly it got worse. I replaced my o2 sensor, Dist. cap and Rotor, and replaced all of my plugs (Bosh (sp) platinum +4)with NGK ones. The car worked fine for about a month now the problem is back but worse, I removed my new plugs today and they are completly black, so is my exhaust pipe so im definatly running very rich. I checked for engine codes but all I got was a 55 which is "no fault" right?. Anyways the misfiring seems to be caused by fouled plugs which is caused by and overly rich mixture, but I don't know what to do about that. I checked my coolant temp sensor + MAF sensor visualy but im not really sure what to look for. Sorry about this long story but this is my first car i've ever worked on and have alot to learn any help would be greatly appreciated Thanks!!

[NISTECH]

Ok Nick a little confused here. your profile says your intrests are "working on cars" and your occupation is a "technician"

Any how you need to use a volt meter to test your maf and also ohm check your coolant temp by following the procedures i have posted in numerous other threads. That would be a place to start.

[OldmanPurdy]

Oh yeah, oops that is a little misleading. I like working on cars im just only been doing it for about 5 months now, and im not a Auto technician im a Copier/POS technician. Anyways moot point now my car failed MVI rust holes and rusty brake lines. Person I bought the car from obvously had some shady guy pass the inspections and being my first car I had no idea what to look for. So it will cost too much to repair properly and will still have rust so I'll just buy a new s13. Perferably one off of NICO. Thanks