just bought a 90 n/a with 88k miles on original engine. car is stock, what are some good reliability mods and tune ups for a high mileage engine.

 

FLUIDS:
- Fuel
- Oil (Don't use any high mileage oils)
- Water/coolant
- Differential oil
- Transmission oil
- Power steering fluid
- Brake fluid
- Clutch fluid

IGNITION:
- Spark plugs (NGK: 2x BUR7EQP and 2x BUR9EQP)
- Spark plug wires
- Be sure the leading coil is grounded well.

FILTERS:
- Fuel filter
- In tank fuel sock (On fuel pump)
- Air filter
- Oil filter

HOSES:
- Radiator and all water/coolant associated hoses
- Check vacuum lines for cracks/breakage (Replace accordingly)
- Fuel hoses (If need be replaced, be sure to get fuel injection rated hose. Also, use proper fuel hose clamps.)
- Brake lines
- Clutch line
- Thoroughly inspect the intake ducting
- Thoroughly inspect the oil cooler hoses

BELTS:
- Air pump belt
- Alternator/water pump belt
- Power steering belt
- Air conditioning belt
(Properly tension all of the above.)

OTHER:
- Master and slave clutch cylinders
- Brake master cylinder
- Brake pads and brake rotors
- Any and all worn suspension bushings
- Test and properly set the Throttle Positioning Sensor(s)
- Have the primary and secondary fuel injectors professionally flow tested and cleaned
- Clean ALL grounds thoroughly (Add extra ground wires if you'd like. Doesn't hurt.)
- Clean battery posts and terminals
- Battery (If needed.)
- Inspect as much of the wiring harness as possible. (Particularly the fuel injector clip wires.)
- Wheel bearings
- Tires
- Struts/springs
- INSPECT and/or REPLACE THE Fuel Pulsation Dampener (A leading cause of engine fires.)
- Inspect the old Metering Oil Pump lines (Tend to crack and break when mishandling... Or touching them in general.)
- Thermostat (Replace with OEM Mazda thermostat.)
- Radiator and water/coolant filler caps
- ANY leaky gaskets and seals (HINT: Water pump housing gasket, moon roof seal, etc...)
- Exhaust donuts
- Exhaust gaskets
- Check all fuses (Driver side kick panel fuses and engine bay fuses.)
- Replace any bad light bulbs
- Replace any bad sensors (Go ahead and get a new O2 sensor.)


There's probably plenty more... But that should be a pretty good start. Pull out your wallet and get to work!

 

alright thats alot of stuff hahaha thanks for the info ill let you know how its going

 

(chuckle!!) ..what HE said!..(whew,I am tired from just lookin at it!)

 

Second to this.

 

thats a great list!!!
for motor oil would you run synthetic or conventional?

 

Conventional always

 

^ +1 Good ol' conventional oil always does the trick.

Personally, I have always used Castrol GTX 20W-50. Over the winter I used 10W-40... Didn't care much for it. The oil burnt up so quickly.

 

changed the oil yersterday. was happy to see alot of oil coming out of it. had a small leak in the pan gotta check on that tomorrow. picked up my sparkies and fuel filter today got to get that done tomorrow as well. if i have time i would like to attempt the lazy look. wish me luck.