New starter with no activity on third and fourth day

I think having whole grain flour in there until you get a good reliable culture helps a lot.  It took me about 2 weeks to get a really solid starter. first week's activities were hit or miss day to day.  i go with a 2-5-5 feeding. 20 grams starter, 50 grams rye 50 grams water.   I  probably could have gone 10g/30g/30g to save on rye flour.  now that i have a reliable one i'm switching to a premixed 25% rye 75% bread flour feed at 2/5/5 daily.

i read that the first few days of activity are more bacteria based.  which builds up acid after which bacteria activity goes down and yeast activity starts to pick up.  you'll know from the nice aroma of alcohol when it's ready.

keep at it. you'll get there.

I've been using the recipe from SourdoLady's blog to make starter from fresh successfully many times (http://www.thefreshloaf.com/blog/sourdolady). 

1. Organic pineapple juice from a can and organic rye flour or whole wheat flour works consistently for me.
2. Converting Sourdolady's recipe from #tablespoons help me feed however much of starter is left until I get more than enough for the next one or two loafs of bread.
3. Room temperature seriously affect how often you need to feed your starter. Basically, once you see the starter shrink after it has more or less doubled in volume, you'll need to feed it again before you use it or store it away in the fridge. I've read many bakers feed their starter twice a day before using it.
4. When building a starter from scratch, I convert Sourdolady's recipe from #tablespoons to #grams to stay accurate to the recipe regardless of whether the flour is packed or loose. I also keep one or two dry packs in my flour container to keep it dry.
5. In your Day 4 and 5 of building your new starter, once it has near doubled and smells pungent, it's ready to be used to make the bread dough. Generally, a mature starter takes only one or two feeding to smell pungent. While when the starter is ready may not coincide with your personal schedule, you often can adjust the amount of time retarding the bread fermentation in the fridge to sync the rest of the process to your schedule. Anywhere from 8 hours to 12 hours in the fridge has worked for me to make the bread sour.

Especially when reviving a starter that has stayed in the fridge for a month or two, I feed it 2-4 times, discarding enough to avoid making too much more starter than needed. I accumulate the discarded starter in the fridge and use it to make sourdough waffles. Here's an important tip, after 3-4 times of doubling the starter when feeding and discarding the excess, the PH in the starter from the pineapple juice will have changed too much that it doesn't promote the growth of the right kind of bacteria that turn the bread sour. I generally include 2 TBS worth of organic pineapple juice in the water I use to double the starter.

I still don't make flat loafs occasionally, especially when I experiment with a new recipe of new flour, but I have been able to consistently keep thy starter alive, or create it from start. Hope this helps.