78 Seville stalling out, backfiring under hood

Does anyone have an idea as to what's causing the following symptoms I'm experiencing with my beloved '78 Seville? On 3 occasions, the motor has fairly rapidly lost power while driving, then completely stalled out after backfiring under the hood. After the car sits for an hour or two, it restarts and drives fine. This has occurred under varying circumstances: full tank of gas, 60 degree air temperatures, driving on the freeway; 1/4 tank of gas, 80 degree air temps, driving stop and go. While the motor is backfiring under the hood, there is the smell of rich fuel/ exhaust. I've had the car to several mechanics with no definitive diagnosis. Thanks very much for any thoughts on this.

Does anyone have an idea as to what's causing the following symptoms I'm experiencing with my beloved '78 Seville? On 3 occasions, the motor has fairly rapidly lost power while driving, then completely stalled out after backfiring under the hood. After the car sits for an hour or two, it restarts and drives fine. This has occurred under varying circumstances: full tank of gas, 60 degree air temperatures, driving on the freeway; 1/4 tank of gas, 80 degree air temps, driving stop and go. While the motor is backfiring under the hood, there is the smell of rich fuel/ exhaust. I've had the car to several mechanics with no definitive diagnosis. Thanks very much for any thoughts on this.
Hello,
I think I can help you with the problem.
Same thing happen to my 1978 Seville.
Call me if you need too.
Charlie Tuttle
843-651-7814

Sounds like a defective fuel pressure regulator. Replace it.

Bad ignition coil. If it's marginal, they work better when cold.....as the engine warms up and the temp under the hood goes up they get worse and worse, and will make the car run exactly as you say.

Today Is Your Lucky Day. I Know Exactly What Is Wrong With Your Seville. I Have A 79 That Had The Exact Same Problem. Ecu Ecu Ecu!!!its Garbage Replace It I Found One On Ebay For $150 Used And If You Look Hard Enough You Can Find Them Rebuilt From $500 To $1000 A Little Hefty I Thought But Thats Not All Ill Bet You A Steak Dinner That Your Coolant Temp Sensor Is Trash Replace It $65-$100 And While Your Hands Are Dirty Go Ahead And Replace Your Throttle Positioning Sensor Odds Are Its A Little Shakey $50-$100 My Car Has Been Running Fine Ever Sense But Keep In Mind Alot Of Parts Youll Find Will Be Used Used 30 Year Old Parts Ive Been Thinking Of Converting Mine Over To Carburation And I Would Suggest U Do The Same My Mechanic Shot Me A Price Of $700 And Said It Would Be Well Worth It No Sense In Fighting 30 Yeal Old Technology

Welcome to AF, I know you are trying to be helpful but look at the dates this is way to old to reply too.