Please Help With Engine Diagnosis; Sputtering, Oily Plugs, can't hold idle or A/F
Last week I changed my spark plugs. To do this with a Kenne Bell supercharger it's must easier to reach the #4 plug if you take the intake tube and throttle body off. This requires disconnecting the throttle position sensor and the actuator connectors. I changed the plugs, put everything back together and drove off to go shopping. It ran like a champ, just like you'd expect with new plugs. I drove about 60 miles, came home and parked.
The next moring the car would barely start. And when it did it was sputtering and unable to hold it's idle and air/fuel ratio. It would start out at 14.7 at idle and slowly dip down to off the scale, below 10:1. It would recover, go lean and start the process all over, the whole time unable to hold a steady idle. When I tried giving any gas it would sputter badly.
Today I took out a spark plug to look at it and it was completely covered from the tip to the threads in an oily goo that smelled like gas. It took the rest out and they are the same, all covered in oily gas goo. This is after only 60 miles on new plugs.
Why did my car suddenly stop working? My first thought was that a MAF sensor or O2 sensor has gone bad. I data logged the MAF and it seems to be working although it's hard to tell since the car runs horribly if at all. But I could see it's voltage rising as I added throttle. I have not checked the O2 sensor yet, I though I'd just get a new one.
Does anyone have any ideas what has happened to my baby? What sensor having to do with A/F can just stop working. Is that theory even sound?
2005 Mustang GT with 300 ci 04 Cobra iron block, Kenne Bell 2.6l twin screw, P&P S3 Heads, SS valves, Comp S3 cams, Currie 9+ 9" rear end and DS, Hurst shifter, BMR K-member, A-arms, LCAs & UCA, JBA long tubes & mid-pipe, Accel COPs, Dual GT500 fuel pumps, much more...
670 RWHP, 640Tq @ 16 psi & 6400 RPM