The belt on the water pump should be less than $ 20.00. A garage should charge a little less than an hours labor. With the car on a hoist, takes about 30 minutes to do the job.
Evidently the cooling fan is not working.
the computer box on a 1992 topaz is on the drivers side under the dashboard on the firewall behind the fuse panel to the left i would think a 1993 would be similar
Only the 2.3L HSC Inline 4 will fit in the 1986 Mercury Topaz. If everything in the engine bay were gutted, perhaps something larger such as a 3.0L V6 from a 1992-1994 model MIGHT fit but it would require a complete running 92-94 Ford Tempo or Mercury Topaz with the V6 engine as a donor car (and, if you could find such a car, it would be more worth your time/money to invest in it v.s. a 1986 model). The automatic transmission from a Taurus WILL NOT WORK in a Tempo/Topaz.
10w30 would be a good choice. Any major brand is fine.
MIght be the injector itself.
Yes, and hopefully nothing else.
A missed adjusted neutral safety switch, or a faulty one.
Low on fluid, dirty filter, worn clutches.
Mercury would not float on water. This is because the density of Mercury (5427kg/m3) is greater than the density of water (1000kg/m3).
In water mercury would sink very quickly as it is very heavy. Keep in mind that part of mercury dissolves in water and is extremely poisonous.
I would have to say say some older model Taurus 82-91
I think it would be the same as a 1993, in which case it is located on the left hand side of the trunk, by the hinge.