http://www.naxja.org/forum/showthread.php?t=1072534
This above link will get you a bit into it by our highly considerate, and helpful resident experts, i.e., how to refresh grounds, (really important), and about why you should absolutely consider a better headlight/harness modification, etc., etc., etc. Consider paying the small amount to keep
up, and going too.
How about revealing more particulars, i.e., auto, or manual transmission, (and type of the latter), lifted, or no lift.., six cylinder is probably simply assumed by us readers.
Get an after-market manual such as the mediocre Haynes, etc., and better still a FSM, or Factory Service Manual for your year--try ebay.
You will need both a digital, and analog multi-meter to make most all RENIX checks, as the diagnostics are different in that it has a French Computer, (ECU), and requires a different official tool, lol, in order to read the data. (it translates French into ENglish.., just kidding).
You might be wise to check all fluids.
1) Try flushing the entire engine/heater anti-freeze mix completely out of the vehicle, and replace with distilled water, and fresh anti-freeze.
2) battery,
3) oil, (and replace oil filter),
4) differentials,
5) transmission,
6) and be sure to grease all grease zerts. While you are around your u-joint zerts, wiggle the shafts for tightness between them, and the joints.
Replace air filter.
Check to make sure your 02 wire is not connecting the exhaust section.
Depending on the mileage, (which would be a bit revealing), your vehicle may, or may not ever had the dreaded "Death Wobble", which may require some front end replacement parts. Try to see if there is any movement between the various front end components with a pry bar, etc.
Consider an alignment of the front end.
You might consider to check all brake linings.
Consider new cap, and rotor, wires, and spark plugs.
Depending how old your shocks are...
If your windshield is old, i.e., micro-pitted, scratches, cracks, etc., consider a replacement.., makes all the difference in the world to have the best forward view under harsh visual conditions, day, or night, rain/snow, or shine.
Replace wind shield wipers for the winter season.
Consider the best tires you can for the winter season in your area.
Renix is old, and for the price you paid for yours, you are ahead of the game as per your indication of it's good condition. Checking, cleaning, replacing the stuff above will go a long way to provide you a safe fun journey.
Oh.., and be sure to often check your fuel rail area for fuel wetness to insure that you are not leaking fuel onto the intake/exhaust manifolds.., a major fire issue problematic with old O-Rings. My '89 has not exhibited such, but I keep my eye on it, as I check my oil level religiously every day before I go anywhere, as well as tug on pulleys, glancing about for radiator leaks, and leaks around about the coolant bottle insuring it has coolant at the proper level, AND never over tighten bottle cap.., just 'snug' it.
Sheesh.., by the time you get done will all of the above it will practically be brand new:cheers: