1991 Buick Riviera • 6 cylinder 2WD Automatic • 120,000 miles

So I own a 1991 buick riviera and it was making a loud sound at the front of the engine and vehicle kept on turning off. I thought it was the water pump bearings so I replaced the water pump. No luck what so ever. After it turns off I shake some harnessed wires that are located on the front of the ignition module where the spark plug wires are connected to. I had the harmonic balancer replaced on it because buick dealer said balancer was broken. $600 later, vehicle now seems to backfire and still turns off. I love this car but my wife doesnt. I dont want to get rid of it but dont want to keep spending more money than the cars worth. Can anybody help me please?
May 28, 2011.

What type of loud sound are you hearing in front of the engine-could be your valve and ignition timing is off causing it to backfire and stalls-You sure its not a tensioner

May 28, 2011.