What PS pump do I have? (And bogging when steering issues)
 

Hey everyone,

My S4 NA bogs down when you try to steer it at a stop. Killed it several times getting it out of the driveway kind of thing, so it's something I'd like to address. From what I have read, I need to double check that my BACV is clean and the idle is adjusted correctly, but I also have some doubts on the origin of my pump. I dont know if mine is S4 or S5, since the old pump has a different shaped reservoir. Maybe an RPM sensing pump would have a communications hiccup with a PS computer expecting a speed sensing one? Would the connectors from an S5 even plug into an S4? Which is this one?

​​​​​​https://cimg4.ibsrv.net/gimg/www.rx7...794f5f710a.jpg
https://cimg5.ibsrv.net/gimg/www.rx7...5bc0459c6b.jpg
https://cimg6.ibsrv.net/gimg/www.rx7...1a9ba8e50e.jpg

Edit: Mobile photo uploading FUBAR

For 86-88 RX7, Mazda lists two different part numbers for power steering pumps depending on your serial number.
FB05-32-600A -7701
FB78-32-600B 7701-
where 7701 FC33* -550169

These pumps are NLA from Mazda.
According to Atkins Rotary (https://www.atkinsrotary.com/store/8...8-32-600B.html), power steering pump FB78-32-600B used from November 1st 1987 - July 1st 1988 from VIN #550170.

Thanks, I will double check my VIN when I'm home. However, searching up both part numbers doesnt identify which pump has which reservoir. I have found this image which has no reference to A or B, but just labels both parts identically. Hardly any help. From this, can I assume that either design is S4 in nature and that the sensors are all for speed-variable steering? And thus, that my pump should be fine for my car?
https://cimg6.ibsrv.net/gimg/www.rx7...13481cddcf.png

Edit: After I uploaded, I noticed the 7701- note in the top left. Oops. Safe to say my pump is a later 600B model then.