Assuming those things you listed are good, it could be a faulty Fuel Pressure Regulator allowing too much fuel into the injectors possibly. He is a how-to to check that from Default
A fairly easy test to see if the FPR is pressuring up too much requires disconnecting the fuel return line (back to the fuel tank) from the rear of the fuel rail. On my 940, this is a simple hose clamp. Be prepared for some fuel to spill. Now get several feet of rubber fuel line hose, slip it over the open end of the fuel rail, and aim it into a gasoline-safe container. Have an assistant start the car, and observe the fuel flow from the hose. You should get a strong stream of fuel, something on the order of 1/2 to 1 gallon per minute. If you get just a trickle or no fuel at all, the FPR is bad. [Tip from Mark Lundell] When you replace the FPR because of a rich burning problem, also replace the little vacuum tube and clean out the intake manifold nipple.
A bad MAF can cause such symptoms as well, but the car would run extremely poorly if at all. A bad ECU can put the wrong amount of fuel into the system too. Might also have a bad Engine Coolant Temperature sensor that goes to the ECU.
I would check this out and go through some of these steps Engine Tune and Performance
A fairly easy test to see if the FPR is pressuring up too much requires disconnecting the fuel return line (back to the fuel tank) from the rear of the fuel rail. On my 940, this is a simple hose clamp. Be prepared for some fuel to spill. Now get several feet of rubber fuel line hose, slip it over the open end of the fuel rail, and aim it into a gasoline-safe container. Have an assistant start the car, and observe the fuel flow from the hose. You should get a strong stream of fuel, something on the order of 1/2 to 1 gallon per minute. If you get just a trickle or no fuel at all, the FPR is bad. [Tip from Mark Lundell] When you replace the FPR because of a rich burning problem, also replace the little vacuum tube and clean out the intake manifold nipple.
A bad MAF can cause such symptoms as well, but the car would run extremely poorly if at all. A bad ECU can put the wrong amount of fuel into the system too. Might also have a bad Engine Coolant Temperature sensor that goes to the ECU.
I would check this out and go through some of these steps Engine Tune and Performance
