I have a 80' 280E that has been difficult to start when it is warm. I finally found the culprit after months of searching. I took off the air cleaner housing and listened to it idle and noticed the cold start valve was making a buzzing noise.

Surely this is the culprit, but it is rather pricey, so does anyone know if there is a quick fix instead of buying a new one?

Also, is the sensor by the exhaust manifold, and if so should I go ahead and replace that too?