'98 Escort stalls while running, loses power

I had a problem in December and you guys here were able to pinpoint it in a day so I've found my way back here. This is the situation this time. I've got a 1998 Ford Escort with 153,000 miles. It's a 4 cylinder. Also, the check engine light works (during bulb test) but it's NOT on when running.

In December the timing belt, serpentine belt, spark plugs/wires, and fuel filter were replaced. The car was running fine for the past 2-3 months except I noticed a lot of vibration in my steering wheel but didn't pay any major attention to it.

Recently while driving the car stalls, it's an intermittent problem. Here's my best explanation. It starts right up with no issues and then I begin driving but it hesitates and it takes a lot to accelerate. Once you get up to about 55/60 or so you can't get any higher and then slowly the car decelerates until you lose all power and stall. When pressing on the gas petal it's like there isn't one.

Here's what is getting me, when you turn the car off and back on you will be able to regain power temporarily until the problem repeats itself.

I've had 3 garages look at it. One told me it was nothing (HAH), one told me the harmonic balancer is bad but wouldn't touch it, and now the 3rd garage has it and he's replacing the harmonic balancer but we've got doubts about that fixing this problem. The pulley is wobbling back and forth as it spins, that was noticed recently.

Does anyone have ANY idea what the problem with this is? I'm up to my wits end trying to diagnose this. If there's anything I left out let me know, I'll be checking back like crazy.