Engine Running Rich


New Member
Nov 8, 2009
I have a 86' GT with a 5.0 HO. I converted it to MAF because of a cam change to a Ford Racing B303 cam. I can't get the engine to stop running rich. I changed the oil when I lost oil pressure and realized it smelled like gas and was very thin. What could be the problem? Are you supposed to change the oxygen sensors to 89-93 sensors or can you keep the old sensors? It dosen't smoke or anything when running. Don't know how fuel is getting past the rings.
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1st off, if you lost oil pressure because of all the fuel in your oil, you've got bigger problems than it running rich, you could have glazed the cylinder walls to the point the rings won't seal. You also could have torn up a bearing in the motor. As far as running rich, is the maf calibrated to your injector size is your fuel pressure appropriate for your setup? What type of maf conversion did you do? Did you change the harness and ecm?
I switched to a 89-93 granatelli ecm calibrated for 19 lb injectors. Mostly stock ecm. also have a granatelli conversion harness, and stock maf sensor for 89 stang. The only thing I can figure is that one of the injectors is staying open after I kill the engine and causing the pressure to leak down. As I said, it's not smoking while the engine running or running rough as if it's bogging down.
The only way I ever convert a car to mass air is w/ a ford mass air harness and a a9l computer. It's possible the calibration could be off in your computer. I doubt you have a sticking injector.