Bought with cash, don't have enough left for big improvements

[Faith Woodward]

We recently bought a house that was built in 1950 and remodeled in the 70s for 78k cash.  The market value for a house this size in this neighborhood that has been improved is around 135k and it needed about 4k for basic aesthetics when we bought it. 

We are about to complete all the asthetic updates (caulking, paint, new vinyl, new carpet), but there are also some more major updates needed that we can't afford in cash right now: 1) $800 of necessary electrical updates to be safe, then additionally upgrading from 100 to 200amp service which will run 2-3k, and 2) there's no central hear and air. It has window units and two large, sufficient but ugly gas heaters.

We'd need about 11k total to finish these bigger things but I don't know if it's wiser to borrow to get it all done now, or wait and let the rental pay for itself.

I don't want to borrow against the house because of closing costs but that is an option.

Any input? Leave it with 100 service and window units and rent for a little less for now? Get more credit cards instead of taking out a small mortgage? Completely update those things before renting?

I realize we should not be in such a tight situation to begin with. We stretched outselves too thin when we decided to buy this place because it was such a good price for this neighborhood and would still bring about 12% ROI even if we spend 11k more, but here we are and I would love advice on how to move forward. Thanks!