I've been dealing with a car that starts and then suddenly dies, I switched the maf sensor for a new one and Now it stays on until I press the gas pedal. The throttle body is clean. Before the car acted up the spark plugs had a nice white/normal look at the tip, now they're fouled. Car lets out a little black smoke andI do recall the car seeming to have unsteady throttle response from none day to the next. My problem is I'm broke and my motorcycle needs repairs also and it's a pretty bad spot so I need to make every dollar count. Another concern is it could be the throttle body, but more signs point towards the fpr. So im just wondering if whoever reads this has knowledge enough to know that the for is the problem Car is a convertable 1999 volvo c70 2.3 t5

I've been dealing with a car that starts and then suddenly dies. I replaced the MAF (Mass Air Flow) sensor with a new one, and now it stays on until I press the gas pedal. The throttle body is clean. 

Before the car acted up, the spark plugs had a nice white/normal look at the tip, now they're fouled. Car lets out a little black smoke, and I do recall the car seeming to have unsteady throttle response from one day to the next. 

My problem is I'm broke, and my motorcycle needs repairs also, and I'm in a pretty bad spot, so I need to make every dollar count. Another concern is that it could be the throttle body, but more signs point towards the FPR (Fuel Pressure Regulator). I'm just wondering if anyone has knowledge enough to know that the FPR is the problem

Car is a convertible 1999 Volvo c70 2.3 t5