If I’ve revived a federal return then amend to add another w-2 how long does it take to get the return. It’s been over 4 month

Are you getting an additional refund?  Usually when you add another W2 your refund is reduced so you would owe some back on an amended return.  Better double check your Amended return.

 Amended returns can only be mailed. It can take them 16 weeks for the IRS to process them. And they only mail checks for refunds. After 3 weeks you can track it here, https://www.irs.gov/filing/individuals/amended-returns-form-1040-x-/wheres-my-amended-return-1 

An amended tax return must be printed, signed, and mailed.  About 3 weeks after you mail in your Form 1040X you should be able to track it on the IRS site.  It generally takes 3-4 months for the IRS to fully process a Form 1040X.  If you are getting a refund, they mail you a check.

https://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1

https://www.irs.gov/filing/individuals/amended-returns-form-1040-x/amended-return-frequently-asked-questions