Anong tagalog ng "I was about to... when...."
Anong tagalog ng "to be about to" + pandiwa + when + pangyayari

Halimbawa:

I was about to open the door when the phone rang.

They were about to give up when they finally heard the good news.

Maraming salamat!

Question

Anong tagalog ng "I was about to... when...."
Anong tagalog ng "to be about to" + pandiwa + when + pangyayari

Halimbawa:

I was about to open the door when the phone rang.

They were about to give up when they finally heard the good news.

Maraming salamat!

Answer

You can use [unstarted form of verb] + [sana]

I was about to open the door when the phone rang.  → Bubuksan ko sana ang pinto nang mag-ring ang telepono.
They were about to give up when they finally heard the good news.  → Susuko na sana sila noong narinig nila ang magandang balita.