I recommend you to change it. If it breaks, then you will need to put some valves in the head.
Any time you buy a used car, change the timing belt, thermostat, air and fuel filters, along with the PCV valve. If the engine is running a little low on power, it is also advised to tuneup the ignition system...
This is the best thingyou can do to ensure the engine will stay with you for as long as possible.
If you want instructions on the timing belt repair, just let me know, and I'll send you some instructions that will save you alot of money. All of this can be done with about $100 in parts, and an afternoon of work.
The filters and ignition system tuneup are pretty starightforward, as well as the PCV valve.
If you want a little more pep without sacrificing very much MPG, you can get a set of performance timing gears, so I have also included instructions on replacing the gears. If you want me to find you a set, just let me know.
Here is an exploded view of the timing cover removal:
Here is the marks for the timing gears.
If reusing the old belt, support the belt so that the meshing of the crankshaft pulley and the timing belt does not shift. Check that the matchmark on the belt matches the end of the No. 1 cover. Align the matchmarks of the belt and the camshaft timing pulley.
Good news, too!! I got confused a little bit about this engine. and... It will NOT bend valves if the timing belt breaks. There are not very many engines that are like this, either. The instructions are for the engine, there is no confusion, there. Still a good idea to change it, though, so it doesn't just quit on the road.
The torque wrench would be a 3/8 drive one. They aren't very expensive at the auto parts store. If you're going to change cam sprockets, you will need the 1/2 ' drive, though.
When you have the engnie torn down, you can also loosen the front mount, and jack it up a little bit to get some extra space in there. They usually drop down a little bit anyway, and you will have enough rooom to work with.