On the timing belt side of the motor. On the timing belt side of the motor.
I had the same issue with a 1990 Mazda 626 and replacing the timing belt cured it.
According to Kelley Blue Book, the estimated value of a 1990 Mazda Miata in excellent condition with approximately 150,000 miles on it is $2,400.
Inside the blower motor housing directly behind the electrical coupler.
5-40 fully synthetic
check thermostat is it opening at all check timing
wiper motor could be going bad
( No ) according to the Gates website ( they make timing belts etcetera ) the 1.9 liter four cylinder engine in a 1990 Ford Escort is NOT an interference engine
Ignition timing refer to Emissioncontrol information label, engine firing order is1,3,4,2.
YOUR 1990 MAX SOULD HAVE A VG30E MOTOR THAT WAS THE STANDARD.AS FOR THE TIMING MARKS THEY ARE NOT RELEVENT TO THE WATER PUMP.BUT ONLY TO THE TIMING BELT.FOR IMFO ON THE R&R OF WATER PUMP TAKE A PEEK AT MY BIO PAGE I'VE GIVE DETAILS TO OTHERS ON THIS SUBJECT....BUDDY MACK
Here you can find the whole instructions how to change your timing belt on a Miata http://www.racecaddy.com/mx5/tech/timing-belt-mx5.html it has good images and it is well explained good luck
The cover on the passenger side of the motor has long lines on it, those are your timing marks. Hold the timing gun above them and look directly down to the crankshaft pully.