Misfiring

[nissans13240sx]

Ok, so you may have read my previous post about the rough idle and running rich... Well it is still doing the same thing, i replaced the o2 back to the stock o2 for the redtop. coolant temp sensor i replaced, the TPS sensor reads 4.4volts so its good. When it is cold it idles at about 1300-1500 which is probably about normal, but when its idleing it will start to bog down and then jump back up. vaccum gauge reads about 20 at 900 rpms. when it starts to warm up thats when it starts running rich and seems to be missing. rpms just jump from about 1000 to 350 and of course when the idle drops is when the black smoke is coming out. Has anyone ever had anything like this? This is really killing me why this **** isnt running right.

[sil8y-X]

Have you checked your MAF?

[nissans13240sx]

would a MAF sensor cause it to misfire though? I could see it causing it to run rich. How do i test the MAF ???

[nissans13240sx]

bump... anyone???

[nissans13240sx]

bump

[S13FASTBACKSR]

yes a maf would/can cause it to misfire..first try cleaning it with electronic cleaner..just spray it on the thermosister dont touch it with your fingers though..if that doesnt fix it then check your voltage..the black wire with a white stripe should be 12v and the white should be 5v..the other wire which is all black is a ground...also your tps reads 4.4volts? this is at w.o.t. correct? if so then that checks out good..if that 4.4volts is at idle then your tps is bad...at idle your tps should be anywhere from .45v - .55v ...also what is your timing set to and your spark plug gap?

[nissans13240sx]

the KA sohc MAFS is the same right? I might just swap it with my one friends to see if it fixes it. The 4.4volts was at WOT. Its about .45 at idle. Thanks for the help im going to try this when i get home today. Ill let you know it turns out

[nissans13240sx]

just wanted to let you guys know, that i got it running good. it idles solid now, and ive been driving it all weekend. i get about 27mpg driving hard. i believe the problem was one the o2 sensor, and second i had my SAFC 2 wires right next to my amp wire. Im guessing my MAFS was affected by this because when i disconnected the safc it ran great but was in safe mode. thanks for your help everyone

[S13FASTBACKSR]

congrats bro