Dparr2ndgen

Greetings folks! I have recently joined the forums as a recent buyer of a gen2 4runner. I bought a 1991 SR5 4runner with the r150f trans and 4x4. I currently love the truck and have found yota tech to be a wealth of information for repairs on the vehicle so far. Up to date I have done all basic maintenance with the exception of a timing belt (will happen soon but since it's non-interference I am not in a rush. However, I am still having issues with the vehicle running rich (occasional raw fuel smell and low power at low rpm.) the only thing currently not working is the speedometer, odometer and trip meter. After reading several threads here I figured it was the mechanical speedometer cable, so yesterday I pulled the cable from the T-case and connected a drill. When I spun the drill counter-clockwise I had no speed register on the gauge cluster. Therefore, today I tried pulling the dash. When the vehicle is moving, the speedo cable (dash side) does soon, however when any "friction" is applied to the cable, it ceases to turn. I am going to try lubricating the cable tonight to see if the stickiness in the housing will go away. However, my main question here is two-fold.

1. Can the speedometer not working affect things like mpg, power, and timing? I read varying statements that since the feed from the t-case is mechanical, that at some point in the dash that signal is transferred to an electrical pulse and sent to the abs, cruise and ECM modules. I also read that being a manual, the cable won't affect anything other than knowing how fast you are going. So does a broken mechanical speedo on a 3vz have the potential to affect engine performance and/or mileage?

2. Since the cable turns on the dash end is it safe to assume that both the cable and transfer case sensor are good? Or is that not a sufficient indicator.

Thank you for your time, please let me know if I need to provide additional information.
Dylan