Ok, let me make sure Im right about this

Coupe NON-Turbo and Convertible use Engine RPM sensing Power Steering

Turbo model use Velocity sensing power steering.

correct ?

cuz I think I have a bad Power Steering pump, and I want to make sure I get the right pump (might get the lines too)

 

Correct.

Double check by checking that your pump has two (engine sensing) or three (speed sensing) lines.

 

I will look at it tomorrow just to be sure.

I have some "hard" steering problem, its still "ok" for now. but I start following the FSM's list so its either lower ball joint and/or the pump itself.

I checked Mazda's price on the pump and it almost gave me an heart attack. so if I have to buy a new pump I just gonna get a re-man one from places like Autozone (lifetime warranty)

 

In 90 and 91.
Non turbos = Engine RPM
Turbo = Velocity

In 1989:
GTU was engine rpm sensing
GXL, Turbo, and Vert was velocity sensing.

 

ahh I see.

I have a 91 NA so im 100% Engine RPM

thx


hmm, just a question, wth is the difference between the 2 ?

 

I believe you are correct.

 

While I am not 100% positive that the Mazda unit works this way, the general idea is:

Both systems adjust the level of power steering applied. So when you are stopped its applying the max help, but when you are moving it applies less help.

Engine speed sensing = Level of help calculated based on engine speed.

Velocity Sensing = Level of help based on road speed.

 

I sort of understand the difference between the 2 system.

but its just weird that Mazda use 2 different system on the same car and Why not just 1 ? space? or ?

oh well, guess we will never know the truth.

 

I would guess that the pump is the same. Only the pressure regulating system is different. Pump only supplies pressure. Regulator controls the output dependent on the sensors.
On GM systems the pump was standard and the software did the various magic dependent on the vehicle..

Close?

DG

 

I really don't know.

the pump looks the same but it has a different part number.

so ...

 

Pumps are different, see my first post:

 

I think the vehicle-speed-sensing steering system must have cost Mazda more to manufacture because they touted it as the "premium" system at the time and generally put it on the more expensive models. Of course, AAS and DTSS were also marketed as beneficial in 1986, and few people think they have any advantages today.

My '90 GTU had the engine-speed-sensing steering and my '88 GTU has the vehicle-speed-sensing steering. I'd say the vehicle-speed version has a tiny bit better feel and is a wee bit heavier. On occasion, it seemed like the steering on the S5 GTU felt a little overassisted. But the difference isn't exactly huge.