Do you do a lot of background research? If not, why not? I do, and here's why:
Some authors spend more time researching their worldbuilding than they do building the words of the stories themselves, and some just sit down with a vague idea and let their characters take the wheel; both are valid, but there are tradeoffs we might not always consider when we're eager to get a story from the brain to the page.
For example, plenty of fiction (both written word and film) treats waking from a coma like waking from a nap; that's simply not the reality, even if it can be a handy plot device. Research can help immensely with suspension of disbelief, especially if the reader is more familiar with the particulars of some scenario you're writing; even if the exact details aren't spelled out in black and white, their implications still matter to those who know enough to look for them.
I'm writing a scene in which a man who had all four limbs broken in a previous chapter gets the casts off; there was no chance of surgical repair and the underequipped doctor has done his best, but the reality of four weeks of complete immobility and scarce food is not a pretty one. Even if the injured man were airlifted out of my story directly to the best rehabilitation facility in the world it would take days to regain most of the movement in the joints, weeks to walk without help, and months of intensive therapy to recover enough strength to call it good enough; the fellow will likely never be as strong, quick, or full of stamina as he was before.
If I were a reader and had never known anyone who was seriously injured, I wouldn't care. I'd be fine with him fighting his way out of the building, outrunning anyone searching for him, or climbing a fence to escape. But having known someone who was bedridden for weeks and took months to bounce back, that would take me right out of the story and add it to my DNF pile on the bottom shelf.
What fraction of potential readers are you willing to turn off to keep from having to do some homework? If you're doing a series, how many sequel sales would it take for you to feel like the extra time is worth it?