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-   -   Ultra light steering (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/ultra-light-steering-556386/)

Bunchies 07-05-06 01:01 AM

Ultra light steering
 
So, after my starter died, I had to compression start the car to get it running for a bit. Well, during this process, I had the key in accessory mode and i had to turn really REALLY hard on the wheel in order to steer it. It seems that after I did this, the steering became much lighter than before. Even after fixing my starting problems, it seems that the steering no longer weights up with rpm/speed/whatever. It's just really light all of the time. At 80mph, I can move the wheel easily with my finger. I suspect I might have screwed something up while manhandling the wheel in accessory mode when the car was off. Any ideas?

SureShot 07-05-06 08:19 AM

If there was a problem with the sensors used to control the steering assist, the stering computer will beep an error code.

The power steering computer has it's own error code system which will emit gentle beeps (versus louder the redline, LOW COOLANT, LOW OIL buzzer) when it encounters a problem with the power steering system.
1-beep, pause, repeat - abnormality of speed sensor signal:
If broken wires or short circuits occur to sensors or harnesses, the beep sounds 60-seconds after the engine speed signal of 2200 rpm continues for 18-seconds.
2-beeps, pause, repeat - abnormality of engine speed signal:
The beep sounds when the vehicle speed signal is input and no engine speed signal is input (short circuit, broken wire, etc.)
3-beeps, pause, repeat - abnormality of stepping motor signal:
The beep sounds when there are broken wires or short circuits in coils or harnesses.
4-beeps, pause, repeat - abnormality of the power steering microcomputer:
The beep sounds when there are circuit troubles other than with the micro computer.
5-beeps, pause, repeat - abnormality of steering sensor signal:
The beep sounds 60-seconds after broken wire or short circuit occurs to sensors or harnesses when the vehicle speed is above 40Km/h (25 mph).
Continuous beep - abnormality of the power steering microcomputer:
The beep sounds if the microcomputer becomes abnormal and cannot control the system.

Icemark 07-05-06 11:06 AM

actually most of the S5 models (and even some 88 models) do not have that error reporting.

They removed the beeper from the circuit board.

anyway, back to the question: If boost is always on, it is either not seeing the speed signal (speedometer needs to work) or the power steering CPU is having issues. You could also have a steering sensor issue or if the trailing coils are not feeding the tach.

Failure of the speed sensor, or tach, or position sensor, can all send the power steering CPU into limp mode with 25% boost at all times instead of just under 15 MPH.

Bunchies 07-05-06 11:17 PM


Originally Posted by Icemark
actually most of the S5 models (and even some 88 models) do not have that error reporting.

They removed the beeper from the circuit board.

anyway, back to the question: If boost is always on, it is either not seeing the speed signal (speedometer needs to work) or the power steering CPU is having issues. You could also have a steering sensor issue or if the trailing coils are not feeding the tach.

Failure of the speed sensor, or tach, or position sensor, can all send the power steering CPU into limp mode with 25% boost at all times instead of just under 15 MPH.

thanks. How would I go about fixing this?

Also, I noticed a tiny bit of leaking fluid when I was changing my starter. Now I have pretty much no idea how steering systems work, but it appeared to be concentrated around the area of the right front wheel. It's hard for me to explain.

HOZZMANRX7 07-05-06 11:52 PM

position sensor??
 
Icemark (or other technical guru),

I have this exact same problem in my '87 TII. However:

1. Speed sensor is working properly evidenced by my cruise control operating properly.
2. I'm certain the Position Sensor is properly aligned. Same number of turns for the steering wheel either way, and the two pins are exact vertical before mounting the steering wheel.
3. Tried two CPU's. The first I got out of a S4 Pic a Part car I'm pretty sure was '87 vintage. This one was beeping (I believe 5 beeps). So, then I put in a different one that came out of an '88 TII. No beeps from that one, but still the same always on power assist. I believe I read that the beeping was eliminated in '88 and later years. So, I left the second one in to at least avoid the constant beeping.
4. Tach is operating properly and engine is running smoothly, so no inndication of a trailing coil problem.

So, the only thing I can think of is the assist controller on the pump that plugs into the harness is bad.

As background, this car originally had manual steering. For the swap I put in a new/rebuilt power rack and pinion, the pump out of the '88TII, and the two different computers mentioned. And, yes, I plugged the pumps assist controller into the harness.

Icemark 07-06-06 12:23 AM


Originally Posted by HOZZMANRX7
Icemark (or other technical guru),

I have this exact same problem in my '87 TII. However:

1. Speed sensor is working properly evidenced by my cruise control operating properly.
2. I'm certain the Position Sensor is properly aligned. Same number of turns for the steering wheel either way, and the two pins are exact vertical before mounting the steering wheel.
3. Tried two CPU's. The first I got out of a S4 Pic a Part car I'm pretty sure was '87 vintage. This one was beeping (I believe 5 beeps). So, then I put in a different one that came out of an '88 TII. No beeps from that one, but still the same always on power assist. I believe I read that the beeping was eliminated in '88 and later years. So, I left the second one in to at least avoid the constant beeping.
4. Tach is operating properly and engine is running smoothly, so no inndication of a trailing coil problem.

So, the only thing I can think of is the assist controller on the pump that plugs into the harness is bad.

As background, this car originally had manual steering. For the swap I put in a new/rebuilt power rack and pinion, the pump out of the '88TII, and the two different computers mentioned. And, yes, I plugged the pumps assist controller into the harness.

5 beeps is indeed the speed sensor. Is there an aftermarket wheel in the car??? I have seen cars with build dates as early as 6/87 not have the beeper in the power steering computer.

If the car didn't have power steering originally it probably didn't have a steering angle sensor anyway. There are two sensors for the steering position feeding into a 8 pin plug. On the cars without power steering from the factory, you will only find 3 or 4 wires in the plug, while models with power steering will have every pin filled with a wire in the plug.

HOZZMANRX7 07-06-06 12:31 AM

Speed sensor's the problem??
 
Not doubting, but how could my cruise control be working properly is the speed sensor is bad? This given all S4's as motion speed cruise as compared to engine speed cruise.

Related, is the speed sensor in the speedometer module itself? I did try a different speedometer module guessing that to be the cause, but no change to the problem.

Further, given it didn't originally have power steering, you're saying no steering angle sensor was installed. So, I take it that the lack of the PS Computer not seeing a signal from a steering angle sensor would not be the cause of always on ps assist? Or, are you saying I need to install an angle sensor from a part car (assuming the plug in is there to the main harnes) to solve the problem?

By the way, it still has the stock steering wheel.

Icemark 07-06-06 12:36 AM

whoops I meant the steering sensor, not the speed sensor. Typo on my part... I was trying to catch up with the 40 or so PMs I got over the last week.

Yep, I bet you have no steering position sensor

HOZZMANRX7 07-06-06 12:40 AM

Got it
 
Next Pic a Part trip, pull a angle sensor from an S4 with Power Steering.

MaczPayne 07-06-06 02:15 AM

These problems are why I'm glad I went with a manual steering rack.

HOZZMANRX7 07-09-06 09:26 PM

Icemark Hits it out of the part again
 
Indeed no steeting angle sensor on the TII. Installed it (it attach's on top of the turn signal sensor), plugged it it, power steering is much happier now. So, to convert manual to poower steering you need.

1. Power Steering rack an pinion.
2. Power Steering pump, hoses, and mounting bracket (same bracket that holds the ac pump. Much different than the on for a manual steering RX7)
3. Steering position sensor. (best to get the whole turn signal/steering sensor unit from a parts car to make it a simple plug and play exercise).


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