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I'm having an issue with my power steering, it's too light at high speeds, feels like I'm gonna die when taking hand off to change gear.
Car has wire in adpatronic all custom engine loom, horseshoe loom is still in use.
So looking at the wiring diagram, my new ecu is obviously not connected to the steering switch
But all the other wiring is connected and my speedo works.
My question is what does the ECU do to this circuit?
Can I just put on 12V and it'll work?
Do I need to set a trigger output that comes on at a certain speed?
What type of signal is the speedo firing out switch? VSS?
Any advice on how this system works is most appreciated, think I'm gonna have to go electric pump sooner than expected!
In the below drawings the only plug not connected on my car is B1-01, which I'm pretty sure is still dangling there!
I think the input to the ECU from the power steering pump is just to tell the ECU that the power steering is under load so it can bump idle up. That's it.
There's also a T in that line going to the speedo, that's the 20,000 mile switch. Mazda for whatever reason decided the idle needed to be a little higher under 20,000 miles.
I don't think the power steering has any input from the ECU. I know the FC did have a speed sensitive power steering that would change the amount of assist with speed. The FD just has the 1 wire coming off the pump, that's just a pressure switch. I think it just grounds out when the pump is under load.
Yes that was my thinking with what the wires do,
Was kinda hoping it was speed sensitive as then that's the solution to my light steering issue!
Could there be an issue with the mechanics of the pump? it must be speed sensitive somehow?
Maybe an alignment thing then,
Thanks Dale, you're a star, was hoping you'd see this lol, nice to see you're still around.
Any ideas on getting my cruise actuator to work with aftermarket ECU? lol
The cruise system is separate from the ECU I do believe. The speedometer outputs a signal to the cruise control computer - as long as you have all the cruise parts (button on dash, steering wheel button, computer, actuator under hood) it should work.
I looked it up since I couldn't remember - the FD's power steering is considered "engine speed sensing" - this means the faster the pump turns, the more assist.
I would suspect alignment if it's twitchy at speed.
I'm having an issue with my power steering, it's too light at high speeds, feels like I'm gonna die when taking hand off to change gear.
That describes exactly how my car used to feel, and I also suspected power steering at first.
Long story short I took it to an alignment shop I trust and got a fresh alignment with more toe-in. Feels waaaaay more stable now, one of those things I wish I had done earlier!
Yeah thanks guys, I'm thinking alignment too heres my settings if you caare to pas comment, the shop I take it too are pretty good so if I say its too twitchy at speed then they should know how to sort it
Originally Posted by DaleClark
The cruise system is separate from the ECU I do believe. The speedometer outputs a signal to the cruise control computer - as long as you have all the cruise parts (button on dash, steering wheel button, computer, actuator under hood) it should work.
My cruise worked when it was an auto, but after the manual swap it never worked. so I've got all the bits yeah.
I'm going to install speedhut gauges soon so the speedo CPU will be gone and I'll be wiring the speed sensor into the ECU (adaptronic).
In an ideal world an output from the ECU could control the cruise actuator.
But I've given up all hope on getting it to work a long time ago! lol so not that bothered
found a thread where you were working on it a while ago that didn't have a definitive answer.
I have a thread all about the cruise control system. Most likely it's a problem with the pedal sensors, either the clutch or brake sensors. It's a pretty basic system when you get down to it.
Main problems I've found have been with the brake switch.
The cruise system is separate from the ECU I do believe. The speedometer outputs a signal to the cruise control computer - as long as you have all the cruise parts (button on dash, steering wheel button, computer, actuator under hood) it should work.
I looked it up since I couldn't remember - the FD's power steering is considered "engine speed sensing" - this means the faster the pump turns, the more assist.
I would suspect alignment if it's twitchy at speed.
Dale
Hi Dale, old thread but, the faster the engine speed, the more assist doesn`t make sense to me. Would this not make the assistance all over the place while running it through the gears? Surely it would have to be speed related, however there is no speed wire going to the fd pump as far as I can see. My totally stock standard 98 FD feels like it needs more PS assistance at parking speeds, however feels perfect at all other driving speeds. I have had several stock FD`s and only this 98 model feels heavy at low speed. Any thoughts appreciated! Steve
Since someone's bumped this up. I might as well update.
I acquired a second-hand pump and rebuilt my PS pump using the best parts from each to make one good one. I used a seals kit I think from Rock Auto and bearing from local bearing shop.
This solved the issue, so it must have been faulty. It had ran dry for a period of time prior to this as the pipe was damaged on a speed bump
if your pump isn't strong enough it probably needs new or rebuild. or just bearing in mind its a 30 year old car and PS isn't what it is now
Never got round to sorting out the cruise, but think I'll be going E-throttle at some point which will allow me to do cruise control that way.
Last edited by joelanger; Mar 6, 2025 at 02:38 PM.