misfire

[98240]

I just installed a new maf and the error codes went away. When I went to drive it, it drove like sh@t. No I am getting a code that says multiple/random misfire detected. Code p0300. ANy suggestions. I am also blowing black smoke out of my exhaust.

370cc injectorswalbro fuel pumpsafc not yet installed

[teddy]

You're running rich. You swapped in a high pressure, high flow fuel pump and bigger injectors without anyway to control the amount of fuel thats being dumped in. The ecu still thinks the injectors are the stock size, so it dumps in more fuel than needed.

Install that safc, punch in the correct injector size, and then see what happens.

[98240]

Ok i will hook it up tommorow. I thought it would run like stock since the ecu thought it was like stock. My wideband reads 10a/f is that rich? I dont want to hook up the safc again since i screwed up my mafs. I guess I should hook i up the right way this time.Thanks for the reply.

[Florida240sx]

you need the safc so your ecu can adjust for the mafs. different in and out signal