racer_ace
racer_ace Reader
5/24/16 8:56 p.m.

The power steering on my '88 RX-7 has apparently given up the ghost. But I can't figure out why. There are no apparent leaks from either the rack, the hoses, or the pump. The fluid level is perfect. The belt is not slipping. The pump sounds fine; i.e. no worn bearing or other noises of any kind. Any thoughts? Are there any common failure points in the system? This car and I have a love-hate relationship. It loves to hate me. It looked like I was going to actually have some time to participate in some auto-x events this summer and now this happens. It may sound silly but if this turns out to be the rack I will probably sell the RX-7 and look for something that will hate me less, as unfortunately, I don't have much time to wrench.

BrokenYugo
BrokenYugo UltimaDork
5/24/16 9:12 p.m.

If it stopped working suddenly and is anything like a saginaw pump, the pump shaft snapped, it will actually slide out if you pop the belt off. If that's what happened I bet it did it somewhere near redline at full lock on a cold day, regulator bypass can't flow fast enough, system pressure and stress on the shaft rises, then the necked down end that the rotor fits on snaps off.

snailmont5oh
snailmont5oh Reader
5/25/16 2:02 a.m.

It sounds like a good time to depower the rack.

wvumtnbkr
wvumtnbkr GRM+ Memberand SuperDork
5/25/16 6:18 a.m.

I know some of these cars have a power steering computer. Any chance it got disconnected or blew a fuse?

It is right by the steering column under the dash.

racer_ace
racer_ace Reader
5/25/16 6:24 a.m.

I will pull the belt and check the pump shaft. I guess I should have seen this coming because recently there were a few times when I had no assist immediately after starting the car. I'd have to turn the wheel a few times. I am also wondering about the actuator (?) on the passenger side of the pump. Maybe it is stuck in the low / no assist position.

From what I've read the recommendation is to not de-power the rack in my model year / trim level because the ratio is such that it is a real bear to drive de-powered. I can say that given the way it is now I could not imagine trying to auto-X the car with the rack de-powered.

wvumtnbkr
wvumtnbkr GRM+ Memberand SuperDork
5/25/16 10:47 a.m.
racer_ace wrote: I will pull the belt and check the pump shaft. I guess I should have seen this coming because recently there were a few times when I had no assist immediately after starting the car. I'd have to turn the wheel a few times. I am also wondering about the actuator (?) on the passenger side of the pump. Maybe it is stuck in the low / no assist position. From what I've read the recommendation is to not de-power the rack in my model year / trim level because the ratio is such that it is a real bear to drive de-powered. I can say that given the way it is now I could not imagine trying to auto-X the car with the rack de-powered.

I have de-powered several 2nd gen RX7 racks. The effort difference is VERY minimal if you depower it the correct way.

We autox and roadrace (for 2+ hours at a time) a 2nd gen with sticky tires that the rack is depowered. My wife has no issues with it.

If you simply take the belt off OR "loop the lines" the effort will be heavier than if you actually cut the seals out of the rack and put some grease in there.

BrokenYugo
BrokenYugo UltimaDork
5/25/16 12:03 p.m.

In reply to racer_ace:

If it went intermittent it's not the shaft, good guess on the solenoid there, I didn't know this was variable assist.

racer_ace
racer_ace Reader
5/25/16 8:19 p.m.

I checked the power steering pump shaft. It appears to be fine. I also checked the fuse for the system. That is fine too. The wiring harness to the actuator (solenoid?) on the pump looks OK. I checked the factory service manual and could not find any info on the actuator (solenoid?) at all. I checked the Mazdatrix site and they don't offer it under the steering or electrical parts. Does anyone know if the actuator (solenoid?) is a serviceable item? Looking at the photos of the power steering pump on Rock Auto it does not look like replacement pumps come with the actuator (solenoid?). Am I barking up the wrong tree? Has anyone ever had this part fail? Thanks in advance. - Ray

BrokenYugo
BrokenYugo UltimaDork
5/25/16 9:27 p.m.

Unplug the solenoid, do you have assist now? I'd assume it gives full pressure when there is no power on it, but it could be the other way around.

racer_ace
racer_ace Reader
5/28/16 11:05 a.m.

Well, I tried disconnecting both the solenoid and pressure switch, in different combinations, with no effect. I'm thinking that next I will try to remove the solenoid and bench check its function...if I can find a pin out for the 6 wires.

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