stiff steering gen-2

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mk8fanatic

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So as it goes, now I need to fix the stiff steering on my blue 97 mark that has a new rack&pin. I thought the speed sensitive steering was normal on it but after I got the ivory 97 mark I noticed that it's steering was so much easier at low speeds. Is there something other than the sensor on the column that I could look at?....something tells me that Driller has the answer :D
 
mk8fanatic said:
...something tells me that Driller has the answer :D
Click to expand...

...LOL, Driller doesn't do Gen2s. :D

But if he did he might find the following excerpts from the manual...

Steering, Power--Variable Assist

The electronic variable orifice (EVO) system is designed to vary the flow from the power steering pump (3A674) as a function of vehicle speed and steering wheel rate of rotation, giving a form of variable assist. The system provides:

  • full power steering assist at low vehicle speed for light parking effort.
  • minimum assist at high speed for good road feel and directional stability.
Click to expand...

Electrical Component Diagnosis

The EVO (electronic variable orifice) control is incorporated into the computer controlled air suspension module. Diagnosis and testing is covered in «Section 04-05A».

NOTE:
The service diagnostic connector is located at the front of the RF shock tower.
Click to expand...

The control module receives inputs from the vehicle speed sensor and the steering sensor. Based on these inputs, the module varies the current to the EVO actuator. At low vehicle speeds and high steering wheel rotation rates, the current to the EVO actuator is low. As vehicle speed is increased, current to the EVO actuator is increased. This reduces power steering pump flow to the steering system, the steering assist is reduced. This results in higher steering effort.
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The control module uses the input from the steering sensor to control the EVO actuator. Voltage is supplied to the sensor through Circuit 298 (P/O). Ground is supplied to the sensor through Circuit 430 (GY). The sensor generates an infrared beam used to control the 5 volt signals supplied to the control module by the sensor through Circuits 633 (R) and 634 (BR). As the steering wheel is turned, the windows in the shutter wheel make and break the infrared beam. This switches the 5 volt signals to zero volts each time the beam passes through one of the windows. The module senses the frequency of these voltage changes and controls the output to the EVO actuator. As the speed increases the EVO actuator decreases power assist by decreasing flow to the steering gear.
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I suggest starting here...

PINPOINT TEST C: DIAGNOSTIC TROUBLE CODE 35: EVO ACTUATOR CONCERN


C1 ELIMINATE EVO ACTUATOR

  • Disconnect EVO actuator harness connector.
  • Connect ohmmeter across EVO actuator terminals; note meter reading.

Does meter indicate less than 8 ohms or more than 16 ohms?

Yes
REPLACE EVO actuator. Repeat «Auto Test» .

No
GO to «C2».
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i was gonna say the evo too, which is part of the air suspension module, all housed together in one case, you might want to try replacing that too, they are cheap enough from ebay, i also have a ton of them in a box. they are all the same from 93-98
same part number on all of them.
 
You are the man!.....now If I just knew where this actuator was. If this was the problem would it be a dealer item?
 
So I guess I need to look at the steering column sensor, the speed sensor which
I don't know where it is, and the actuator which I also don't know where it is.
 
mk8fanatic said:
So I guess I need to look at the steering column sensor, the speed sensor which
I don't know where it is, and the actuator which I also don't know where it is.
Click to expand...

I've never heard of an issue with the steering column sensor - but I have heard of several EVO actuators failing. It is on the discharge side of the power steering pump and I believe has a 2-wire harness connector. I can get more details from the manual tonight.
 
Think I could easily unplug the sensor on the column to see if the steering is effected, in turn telling me if its working or if its the balljoints?
 
I have narrowed it down to the speed sensor or the pump/actuator. I may just do both. Speed sonsor is on the tranny right?
 
Has anyone heard about flushing out all the old steering fluid and replaceing it with Mercon 5 to make it steer easier? If so would that be a power steering mercon 5 or the tranny fluid?
 
I think the PS fluid calls for Regular Mercon which is Mercon III... and Mercon III and V don't mix... So I would suggest sticking with III.
 
Uh O! I think that may be what I did wrong.....I dunno what is in your standard power steering fluid but thats what I put in it when I changed the rack&pin....boy do I feel dumb.
 
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That fluid is usually much thicker than the Mercon that comes from the factory. Because it has lots of additives to prevent leaks etc since most buyers of that stuff use it in old leaking racks (lol).

I noticed a much firmer feel when I switched over to that stuff in my 1993 Cougar back in the day...

The fluid is also usually clear vs Red for Mercon.
 
Any advice on how to get most of it out....or is my best bet to take off the line on the pump and empty the pump/reservoir, and do this several times?
 
Or buy a cheap turkey baster (or steal Mom's or wife's) and suck it out. That's what I did just to change the fluid. Bought Mercon V for mine. Works great. Oh, BTW, if you use the turkey baster from the house, don't put it back!! LOL
 
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