When you first start the 1995 Oldsmobile, 3800 V-6, it turns over like it has no gas or is flooded. It finally starts but dies immediately. If you pump the gas pedal as you start it after the first time, it will spit and backfire. Eventually it will run and run at fast idle, but needs the gas pedal pumped until it warms up. It will then idle. You put in reverse, back out, put in gear and it will bog down and have no power if you press the gas pedal to hard. Any clues to the problem? Have changed the plugs, gas filter and put lots of fuel injector cleaner in the tank.