Looking on the internet deeply has found these results:

i was working is the most popular phrase on the web.

I were working 140,000 results on the web	i was working 169,500,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
butyllithium... I've pretty obsessively covered the UCLA/ Sheharbano "Sheri" Sangji case with two hats: as a blogger�... May 11, 2009 ... If I were working with tert I was working, I were working. you were working, you were working. he was working, he were working. she was working, she were working. it was working, it �... A long time ago, I was in Burma. My friends and I were working for the local government. They were trying to buy the loyalty of tribal leaders by bribing them with�... Feb 1, 2012 ... Neil Young: Steve Jobs and I were working on new iPod. Singer tells technology conference he and the late Apple boss planned audiophile�...	It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

I were working

140,000 results on the web

i was working

169,500,000 results on the web

More popular!

butyllithium... I've pretty obsessively covered the UCLA/ Sheharbano "Sheri" Sangji case with two hats: as a blogger�...
May 11, 2009 ... If I were working with tert
I was working, I were working. you were working, you were working. he was working, he were working. she was working, she were working. it was working, it �...
A long time ago, I was in Burma. My friends and I were working for the local government. They were trying to buy the loyalty of tribal leaders by bribing them with�...
Feb 1, 2012 ... Neil Young: Steve Jobs and I were working on new iPod. Singer tells technology conference he and the late Apple boss planned audiophile�...

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.