Crown Victoria P71 running rich

My 2000 Crown Vic runs rich. It craps out on acceleration, but runs decent on light throttle and idles good. Fuel pressure is 32-40 psi, vacuum is steady at 20in.,MAF sensor is with in spec according to my scanner, and it has no codes in the computer. The long term fuel trim reads negative so it is running rich. I disconected the evap system from the intake and that made no difference. I disconected the MAF and it made no difference in how it ran but it did show a code. I reconected it, and the reading on the scanner went back to normal. I'm starting to think the computer is bad but don't want to buy parts on a guess. Any ideas would be helpful.

have you checked your o2 sensors ,they tell the computer how your car is running if they are clogged they could be sending a lean signal causing the computer to run rich.

My scanner showed a bad O2 sensor so I replaced it, but no luck. On a whim I pulled all the coils off and looked at the boots and down in the spark plug holes. Two on the driver's side were crusty looking. I cleaned them up, put it together and it runs great. Appearently the Coil on Plug set up is prone to getting dirt and water down in the plug hole. The computer never showed a misfire but the dirt was enough that under a load it would misfire. If I ever have another modular engine that runs crappy I will definately check that first!