I have a 1991 V6 3.0 Automatic Pickup. Recently it has sputtered at idle and while in drive. I can rev it up in park and its fine but when you let go, theres the issue. It bogs down and sputters so bad that it will shut off. If i try to put it in drive, it will drive, pedal to the ground at 20mph max. I put new cap and rotor and plugs and wires in. Changed the distributor, fuel filter, and the MAFS. Help please!