Your 1984 2.5 four should never ever need an adjustment.
But if you have noisy valves, remove air cleaner and valve cover.
Check valve lift (it is likely if you have noisy valves the camshaft has failed)
If all checks good, Rotate engine until each valve is on the base circle of the cam, adjust valve until there is no lash or slop in the rocker and tighten an additional 1/2 turn.
There is no fan belt on any year Fiero. Electric fan motor,
my uncles 84 fiero only opens with keys. My Fiero has a button on the top right of the gauge cluster that will open the trunk. It has to have a battery or the engine running to do so though.
The reason behind the over heating of your fiero is the fact its an RMR layout and your cooling system is in the front end of the car. The time the coolant travels is not quick enought to cool the engine as fast as it is needed.
Yes It would be esiest if yu has a 1985 V6 Fiero car to get parts off This will require a replacement computer and a bunch of custom wiring and shifter work to get running otherwise. Good Luck
150 ci
145 kmph or around 90 mph according to Pontiac spec. A good running car can easily beat this by 5 mph (at least mine did)
Three basic reasons The fan does not work The cooling system has an air lock (very common) Cracked head, this engine is notorious for doing this
The listed rating of the 1984 4-cylinder Fiero is : 94hp (if I recall correctly)
The Fiero Store: http://www.fierostore.com/Product/Browse.aspx?d=281&p=1
On a scale of 1 to 10 its about a 5 for actual dificulty. For pain and tight space to work in they are about a 11 due to sharp edges.
4 speed manual Muncie Performance Transmission. The other 84's used the 4spd performance and 4 speed Economy trans. Made in Muncie Indiana.
This is a pretty simple system The most common failure is the sensor But the relay located under the left front headlight or the fuse could fail And lastly the fan could be bad