Idle Control Valve - 88' 190e 2.3L

[gards]

My mechanic discover, while troubleshooting due to the car dying as it comes to a stop, that my Idle Control Valve is sticking. He remove the wire and the engine revs came up a bit. However, he mentioned that it should cause the revs to come up to about 1400 - 1500 rpms. So we left the wire disconnected and the car has not died since. However, may questions is this:

Could that Idle Control Valve becausing poor fuel mileage and performance? I ask because it is the Idle Control Valve and I am wondering if after you get the car in motion does it still factor into fuel mileage and performance.

Any thoughts would be welcomed. I can replace with a used one for about $75 or $180 new, and I am wondering if it is worth it.

Thanks,

Gards