Why is my car running so ritch??

[AN89HATCH]

It seems as tho my car is runnign very ritch, My car used to be ka turbo (then i sold everything) and went back to all motor, I still ahve my walbro hp 255lph fuel pump in the car, and thats all i kept from swaping back to all motor. It ran normal for about 6 monts, but lately it seems to be running really ritch, my gas milage is really bad, and now my car is shooting out fire balls. But i checked my spark plugs, and they are not fouled which is weird. will just leaving the hp fuel pump in the car cause it to run rich, and back fire alot?

[s13gonwild]

fireballs? hehe take a vid...leave it alone it looks cool LOL do you have a fuel regulator or sumthing like that?

[bdeisle]

check the o2 sensor

[trixxxr4_kids]

o2 sensor , MAF or if your lucky your air filter is dirty and your ECU is trying to compensate for the loss of air with gas :duh:

[97SilviaRB]

fuel pump or o2 sensor

[papershot]

fuel pump wont make you run rich. the fuel pressure regulator is there for that purpose.