The car has been stalling at idle for a while now. Everything I have done so far seems to have NOT resolved the issue. I have changed the spark plugs, wires, distributor cap and rotor. I've also installed a new IAC Valve and cleaned the throttle body and MAF.

At first the car had a very very rough/low idle where it would start stalling out. It turned out to be that the spark plugs were loose and tightened them up. Also, cleaned the throttle body after. This seemed to have fixed the rough idle issue, and everything was good for a couple days. At idle, it still began to stall only sometimes. Happens more often on cold starts. I thought it was the iac so I got the $400 valve and had it installed. I started to get some really weird symptoms like the engine cutting out for half a second while driving causing it to jerk really hard. There was also a pull when taking foot off the gas and hesitation when trying to accelerate. Took it to the shop and they could not replicate the problem. They cleaned the throttle body again and it drove fine for a two days. Now it stalled again when I had to come to a stop and immediately press the gas again.

I'm wondering if the throttle body itself is beginning to fail or the fuel pump may be on its way out. Any suggestions?